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Question 12221: Affine Shifts Drop Out of Covariance

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

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R0023-12221 · q-20261013-advance-20261026-r05-covariance-0071

Original question and givens

Use the complete list of distinct integer pairs=[[8, -1], [9, 0], [10, 1], [11, 2]] and their aligned exact masses=[1/8, 1/4, 1/8, 1/2] on one common finite probability space. Qualification requires every mass to be nonnegative and their exact sum to be 1; zero masses are allowed. Preserve pair-mass alignment. Marginals alone do not specify this joint law or imply independence. No continuous or infinite-support conclusion is claimed. Use exact reduced rational outputs with positive denominators; omit /1 for integers. Require a qualified joint table. Transform to aX+b and cY+d with [a,b,c,d]=[3, 8, -2, -8]. Give (a,b,c,d,covariance,transformed_covariance,Cov(aX+b,cY+d)=ac Cov(X,Y)).

  • G001 — Use the complete list of distinct integer pairs=[[8, -1], [9, 0], [10, 1], [11, 2]] and their aligned exact masses=[1/8, 1/4, 1/8, 1/2] on one common finite probability space. Qualification requires every mass to be nonnegative and their exact sum to be 1; zero masses are allowed. Preserve pair-mass alignment. Marginals alone do not specify this joint law or imply independence. No continuous or infinite-support conclusion is claimed. Use exact reduced rational outputs with positive denominators; omit /1 for integers. Require a qualified joint table. Transform to aX+b and cY+d with [a,b,c,d]=[3, 8, -2, -8]. Give (a,b,c,d,covariance,transformed_covariance,Cov(aX+b,cY+d)=ac Cov(X,Y)).

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

Step-by-step derivation

S001 · calculation

Before

joint law total mass := sum(1/8, 1/4, 1/8, 1/2)

After

joint law total mass = 1

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001

S002 · implies

Before

original distinct joint pairs=[[8, -1], [9, 0], [10, 1], [11, 2]];raw aligned masses=[[1, 8], [1, 4], [1, 8], [1, 2]]

After

normalized aligned masses=[1/8, 1/4, 1/8, 1/2];nonnegative=Yes;total=1

Conditions: none

Use the complete original joint table on one common probability space,preserving order,pairing and zero masses.Covariance requires nonnegative masses with exact total1.

Step identifiers and dependencies

Rule: qualify_whole_joint_law_preserve_alignment · Uses: G001, S001

S003 · calculation

Before

original atom0 weighted X := mul(1/8, 8)

After

original atom0 weighted X = 1

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

original atom0 weighted Y := mul(1/8, -1)

After

original atom0 weighted Y = -1/8

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

original atom0 XY := mul(8, -1)

After

original atom0 XY = -8

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

original atom0 weighted XY := mul(1/8, -8)

After

original atom0 weighted XY = -1

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

original atom1 weighted X := mul(1/4, 9)

After

original atom1 weighted X = 9/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

original atom1 weighted Y := mul(1/4, 0)

After

original atom1 weighted Y = 0

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

original atom1 XY := mul(9, 0)

After

original atom1 XY = 0

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

original atom1 weighted XY := mul(1/4, 0)

After

original atom1 weighted XY = 0

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

original atom2 weighted X := mul(1/8, 10)

After

original atom2 weighted X = 5/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

original atom2 weighted Y := mul(1/8, 1)

After

original atom2 weighted Y = 1/8

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

original atom2 XY := mul(10, 1)

After

original atom2 XY = 10

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

original atom2 weighted XY := mul(1/8, 10)

After

original atom2 weighted XY = 5/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · calculation

Before

original atom3 weighted X := mul(1/2, 11)

After

original atom3 weighted X = 11/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · calculation

Before

original atom3 weighted Y := mul(1/2, 2)

After

original atom3 weighted Y = 1

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · calculation

Before

original atom3 XY := mul(11, 2)

After

original atom3 XY = 22

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · calculation

Before

original atom3 weighted XY := mul(1/2, 22)

After

original atom3 weighted XY = 11

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

original E_X := sum(1, 9/4, 5/4, 11/2)

After

original E_X = 10

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

original E_Y := sum(-1/8, 0, 1/8, 1)

After

original E_Y = 1

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · calculation

Before

original E_XY := sum(-1, 0, 5/4, 11)

After

original E_XY = 45/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S020

S022 · calculation

Before

original product of means := mul(10, 1)

After

original product of means = 10

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S021

S023 · calculation

Before

original covariance := sub(45/4, 10)

After

original covariance = 5/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S022

S024 · implies

Before

original:E_X=10;E_Y=1;E_XY=45/4

After

Cov=E_XY-E_X*E_Y=5/4

Conditions: none

All three expectations use the same atoms and masses.Do not mix marginal models or assume independence.

Step identifiers and dependencies

Rule: covariance_same_joint_three_moments · Uses: G001, S023

S025 · calculation

Before

affine atom0 scaled X := mul(3, 8)

After

affine atom0 scaled X = 24

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · calculation

Before

affine atom0 U := sum(24, 8)

After

affine atom0 U = 32

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S025

S027 · calculation

Before

affine atom0 scaled Y := mul(-2, -1)

After

affine atom0 scaled Y = 2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S026

S028 · calculation

Before

affine atom0 V := sum(2, -8)

After

affine atom0 V = -6

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S027

S029 · calculation

Before

affine atom1 scaled X := mul(3, 9)

After

affine atom1 scaled X = 27

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S028

S030 · calculation

Before

affine atom1 U := sum(27, 8)

After

affine atom1 U = 35

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S029

S031 · calculation

Before

affine atom1 scaled Y := mul(-2, 0)

After

affine atom1 scaled Y = 0

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S030

S032 · calculation

Before

affine atom1 V := sum(0, -8)

After

affine atom1 V = -8

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S031

S033 · calculation

Before

affine atom2 scaled X := mul(3, 10)

After

affine atom2 scaled X = 30

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S032

S034 · calculation

Before

affine atom2 U := sum(30, 8)

After

affine atom2 U = 38

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S033

S035 · calculation

Before

affine atom2 scaled Y := mul(-2, 1)

After

affine atom2 scaled Y = -2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S034

S036 · calculation

Before

affine atom2 V := sum(-2, -8)

After

affine atom2 V = -10

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S035

S037 · calculation

Before

affine atom3 scaled X := mul(3, 11)

After

affine atom3 scaled X = 33

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S036

S038 · calculation

Before

affine atom3 U := sum(33, 8)

After

affine atom3 U = 41

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S037

S039 · calculation

Before

affine atom3 scaled Y := mul(-2, 2)

After

affine atom3 scaled Y = -4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S038

S040 · calculation

Before

affine atom3 V := sum(-4, -8)

After

affine atom3 V = -12

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S039

S041 · calculation

Before

affine transformed atom0 weighted X := mul(1/8, 32)

After

affine transformed atom0 weighted X = 4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S040

S042 · calculation

Before

affine transformed atom0 weighted Y := mul(1/8, -6)

After

affine transformed atom0 weighted Y = -3/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S041

S043 · calculation

Before

affine transformed atom0 XY := mul(32, -6)

After

affine transformed atom0 XY = -192

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S042

S044 · calculation

Before

affine transformed atom0 weighted XY := mul(1/8, -192)

After

affine transformed atom0 weighted XY = -24

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S043

S045 · calculation

Before

affine transformed atom1 weighted X := mul(1/4, 35)

After

affine transformed atom1 weighted X = 35/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S044

S046 · calculation

Before

affine transformed atom1 weighted Y := mul(1/4, -8)

After

affine transformed atom1 weighted Y = -2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S045

S047 · calculation

Before

affine transformed atom1 XY := mul(35, -8)

After

affine transformed atom1 XY = -280

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S046

S048 · calculation

Before

affine transformed atom1 weighted XY := mul(1/4, -280)

After

affine transformed atom1 weighted XY = -70

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S047

S049 · calculation

Before

affine transformed atom2 weighted X := mul(1/8, 38)

After

affine transformed atom2 weighted X = 19/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S048

S050 · calculation

Before

affine transformed atom2 weighted Y := mul(1/8, -10)

After

affine transformed atom2 weighted Y = -5/4

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S049

S051 · calculation

Before

affine transformed atom2 XY := mul(38, -10)

After

affine transformed atom2 XY = -380

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S050

S052 · calculation

Before

affine transformed atom2 weighted XY := mul(1/8, -380)

After

affine transformed atom2 weighted XY = -95/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S051

S053 · calculation

Before

affine transformed atom3 weighted X := mul(1/2, 41)

After

affine transformed atom3 weighted X = 41/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S052

S054 · calculation

Before

affine transformed atom3 weighted Y := mul(1/2, -12)

After

affine transformed atom3 weighted Y = -6

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S053

S055 · calculation

Before

affine transformed atom3 XY := mul(41, -12)

After

affine transformed atom3 XY = -492

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S054

S056 · calculation

Before

affine transformed atom3 weighted XY := mul(1/2, -492)

After

affine transformed atom3 weighted XY = -246

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S055

S057 · calculation

Before

affine transformed E_X := sum(4, 35/4, 19/4, 41/2)

After

affine transformed E_X = 38

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S056

S058 · calculation

Before

affine transformed E_Y := sum(-3/4, -2, -5/4, -6)

After

affine transformed E_Y = -10

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S057

S059 · calculation

Before

affine transformed E_XY := sum(-24, -70, -95/2, -246)

After

affine transformed E_XY = -775/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S058

S060 · calculation

Before

affine transformed product of means := mul(38, -10)

After

affine transformed product of means = -380

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S059

S061 · calculation

Before

affine transformed covariance := sub(-775/2, -380)

After

affine transformed covariance = -15/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S060

S062 · implies

Before

affine transformed:E_X=38;E_Y=-10;E_XY=-775/2

After

Cov=E_XY-E_X*E_Y=-15/2

Conditions: none

All three expectations use the same atoms and masses.Do not mix marginal models or assume independence.

Step identifiers and dependencies

Rule: covariance_same_joint_three_moments · Uses: G001, S061

S063 · calculation

Before

affine two scale product := mul(3, -2)

After

affine two scale product = -6

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S062

S064 · calculation

Before

affine scaled original covariance := mul(-6, 5/4)

After

affine scaled original covariance = -15/2

Conditions: none

Compute exactly from the specified source roles and established intermediates,without substituting models,reordering pairings or comparing rounded values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S063

S065 · implies

Before

U=(3)*X+(8);V=(-2)*Y+(-8);same indexed atoms and weights

After

E_UV-E_U*E_V=(3)*(-2)*(E_XY-E_X*E_Y)=-15/2

Conditions: none

Expand E[UV]=acE[XY]+adE[X]+bcE[Y]+bd and subtract(aE[X]+b)(cE[Y]+d);all shift terms cancel.Even zero scaling may duplicate image points:retain original probability atoms rather than treating images as a new distinct support.

Step identifiers and dependencies

Rule: affine_covariance_shift_cancellation_not_new_joint_support · Uses: G001, S064

Reverse checks

  • S065 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S064 · premise_and_result_audit — Recompute affine scaled original covariance with exact rational arithmetic, not rounded decimals.
  • S063 · premise_and_result_audit — Recompute affine two scale product with exact rational arithmetic, not rounded decimals.
  • S062 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S061 · premise_and_result_audit — Recompute affine transformed covariance with exact rational arithmetic, not rounded decimals.
  • S060 · premise_and_result_audit — Recompute affine transformed product of means with exact rational arithmetic, not rounded decimals.
  • S059 · premise_and_result_audit — Recompute affine transformed E_XY with exact rational arithmetic, not rounded decimals.
  • S058 · premise_and_result_audit — Recompute affine transformed E_Y with exact rational arithmetic, not rounded decimals.
  • S057 · premise_and_result_audit — Recompute affine transformed E_X with exact rational arithmetic, not rounded decimals.
  • S056 · premise_and_result_audit — Recompute affine transformed atom3 weighted XY with exact rational arithmetic, not rounded decimals.
  • S055 · premise_and_result_audit — Recompute affine transformed atom3 XY with exact rational arithmetic, not rounded decimals.
  • S054 · premise_and_result_audit — Recompute affine transformed atom3 weighted Y with exact rational arithmetic, not rounded decimals.
  • S053 · premise_and_result_audit — Recompute affine transformed atom3 weighted X with exact rational arithmetic, not rounded decimals.
  • S052 · premise_and_result_audit — Recompute affine transformed atom2 weighted XY with exact rational arithmetic, not rounded decimals.
  • S051 · premise_and_result_audit — Recompute affine transformed atom2 XY with exact rational arithmetic, not rounded decimals.
  • S050 · premise_and_result_audit — Recompute affine transformed atom2 weighted Y with exact rational arithmetic, not rounded decimals.
  • S049 · premise_and_result_audit — Recompute affine transformed atom2 weighted X with exact rational arithmetic, not rounded decimals.
  • S048 · premise_and_result_audit — Recompute affine transformed atom1 weighted XY with exact rational arithmetic, not rounded decimals.
  • S047 · premise_and_result_audit — Recompute affine transformed atom1 XY with exact rational arithmetic, not rounded decimals.
  • S046 · premise_and_result_audit — Recompute affine transformed atom1 weighted Y with exact rational arithmetic, not rounded decimals.
  • S045 · premise_and_result_audit — Recompute affine transformed atom1 weighted X with exact rational arithmetic, not rounded decimals.
  • S044 · premise_and_result_audit — Recompute affine transformed atom0 weighted XY with exact rational arithmetic, not rounded decimals.
  • S043 · premise_and_result_audit — Recompute affine transformed atom0 XY with exact rational arithmetic, not rounded decimals.
  • S042 · premise_and_result_audit — Recompute affine transformed atom0 weighted Y with exact rational arithmetic, not rounded decimals.
  • S041 · premise_and_result_audit — Recompute affine transformed atom0 weighted X with exact rational arithmetic, not rounded decimals.
  • S040 · premise_and_result_audit — Recompute affine atom3 V with exact rational arithmetic, not rounded decimals.
  • S039 · premise_and_result_audit — Recompute affine atom3 scaled Y with exact rational arithmetic, not rounded decimals.
  • S038 · premise_and_result_audit — Recompute affine atom3 U with exact rational arithmetic, not rounded decimals.
  • S037 · premise_and_result_audit — Recompute affine atom3 scaled X with exact rational arithmetic, not rounded decimals.
  • S036 · premise_and_result_audit — Recompute affine atom2 V with exact rational arithmetic, not rounded decimals.
  • S035 · premise_and_result_audit — Recompute affine atom2 scaled Y with exact rational arithmetic, not rounded decimals.
  • S034 · premise_and_result_audit — Recompute affine atom2 U with exact rational arithmetic, not rounded decimals.
  • S033 · premise_and_result_audit — Recompute affine atom2 scaled X with exact rational arithmetic, not rounded decimals.
  • S032 · premise_and_result_audit — Recompute affine atom1 V with exact rational arithmetic, not rounded decimals.
  • S031 · premise_and_result_audit — Recompute affine atom1 scaled Y with exact rational arithmetic, not rounded decimals.
  • S030 · premise_and_result_audit — Recompute affine atom1 U with exact rational arithmetic, not rounded decimals.
  • S029 · premise_and_result_audit — Recompute affine atom1 scaled X with exact rational arithmetic, not rounded decimals.
  • S028 · premise_and_result_audit — Recompute affine atom0 V with exact rational arithmetic, not rounded decimals.
  • S027 · premise_and_result_audit — Recompute affine atom0 scaled Y with exact rational arithmetic, not rounded decimals.
  • S026 · premise_and_result_audit — Recompute affine atom0 U with exact rational arithmetic, not rounded decimals.
  • S025 · premise_and_result_audit — Recompute affine atom0 scaled X with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S023 · premise_and_result_audit — Recompute original covariance with exact rational arithmetic, not rounded decimals.
  • S022 · premise_and_result_audit — Recompute original product of means with exact rational arithmetic, not rounded decimals.
  • S021 · premise_and_result_audit — Recompute original E_XY with exact rational arithmetic, not rounded decimals.
  • S020 · premise_and_result_audit — Recompute original E_Y with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute original E_X with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute original atom3 weighted XY with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Recompute original atom3 XY with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Recompute original atom3 weighted Y with exact rational arithmetic, not rounded decimals.
  • S015 · premise_and_result_audit — Recompute original atom3 weighted X with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Recompute original atom2 weighted XY with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute original atom2 XY with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute original atom2 weighted Y with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute original atom2 weighted X with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute original atom1 weighted XY with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute original atom1 XY with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute original atom1 weighted Y with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute original atom1 weighted X with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute original atom0 weighted XY with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute original atom0 XY with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute original atom0 weighted Y with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute original atom0 weighted X with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S001 · premise_and_result_audit — Recompute joint law total mass with exact rational arithmetic, not rounded decimals.

Result

(3, 8, -2, -8, 5/4, -15/2, Cov(aX+b,cY+d)=ac Cov(X,Y))

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: cfab7fe69011e374f633a7362db3d62c10ff17c91089623fa64df089c45b603a
  • candidate record SHA-256: c9187177a8f35fd11d4e65f53412f305817de6dc75546bd49b409a88a0acf419
  • semantic review receipt SHA-256: f783e81f44ff0faa13dbf948657e9187244a59a809ebdf96f22cca24966649ff
  • question-first witness SHA-256: 49a50ed0550be55124d6562260c2ccf4fa6d3f316d7ad9d0d32174400e362e18
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON