原題與已知條件
非空有限 S={0, 1, 2, 3}、事件族 F=𝒫(S),總函數 X:S→R 的值表為 {(0, -19), (1, -19), (2, 20), (3, 1017)},各結果依列序 [0, 1, 2, 3] 的非負機率權重為 [1/24, 20/24, 3/24, 0/24],權重總和恰為一。求精確 P(X=1017),以最簡正分母 p/q 回答。
G001 — 非空有限 S={0, 1, 2, 3}、事件族 F=𝒫(S),總函數 X:S→R 的值表為 {(0, -19), (1, -19), (2, 20), (3, 1017)},各結果依列序 [0, 1, 2, 3] 的非負機率權重為 [1/24, 20/24, 3/24, 0/24],權重總和恰為一。求精確 P(X=1017),以最簡正分母 p/q 回答。
逐步推導
S001 · implies
操作前
source roles = [qf-random-variable-point-mass, rv_point_mass]
操作後
derived = [probability_of_complete_value_fibre]
條件:無
本題輸出依原scalar/set/是非/fraction角色;有理數整數保留/1。不加未宣告domain,不改中英來源、公式或題目。
步驟識別與依賴
規則:R56_source_answer_role_and_EXACT_family_interface · 依賴:G001
S002 · implies
操作前
source roles = [[0, 1, 2, 3], powerset(S), [-19, -19, 20, 1017]]
操作後
derived = [[[0, -19], [1, -19], [2, 20], [3, 1017]]]
條件:無
values逐slot對齊原S,不能把兩列分開排序。有限full powerset包含每個X的逆像,故這個實值函數可測;求value/range/event不須另造均勻權重。
步驟識別與依賴
規則:RV_full_powerset_measurability_ORIGINAL_outcome_value_alignment · 依賴:G001, S001
S003 · calculation
操作前
RV ORIGINAL all aligned numerator weights := sum(1, 20, 3, 0)
操作後
RV ORIGINAL all aligned numerator weights = 24
條件:無
按本題原始角色作精確有理運算;SAFE只約束原輸入,衍生整數不截斷,不作浮點近似。
步驟識別與依賴
規則:exact_rational_arithmetic · 依賴:G001, S002
S004 · implies
操作前
source roles = [[[0, -19, 1], [1, -19, 20], [2, 20, 3], [3, 1017, 0]], 24, 1017]
操作後
derived = [24, [[0, -19, 1, 否], [1, -19, 20, 否], [2, 20, 3, 否], [3, 1017, 0, 是]]]
條件:無
同一S的非負權重總和須等den>0;P(X=t)加完整fiber的權重,重複X值不可只取首項,零權重也保留。不以range大小作分母。
步驟識別與依賴
規則:RV_point_mass_normalized_law_ON_S_and_ALL_fibre_terms · 依賴:G001, S003
S005 · calculation
操作前
RV ORIGINAL matching slot3 outcome3 mass := sum(0, 0)
操作後
RV ORIGINAL matching slot3 outcome3 mass = 0
條件:無
按本題原始角色作精確有理運算;SAFE只約束原輸入,衍生整數不截斷,不作浮點近似。
步驟識別與依賴
規則:exact_rational_arithmetic · 依賴:G001, S004
S006 · calculation
操作前
RV ORIGINAL complete fibre mass over denominator := div(0, 24)
操作後
RV ORIGINAL complete fibre mass over denominator = 0
條件:無
按本題原始角色作精確有理運算;SAFE只約束原輸入,衍生整數不截斷,不作浮點近似。
步驟識別與依賴
規則:exact_rational_arithmetic · 依賴:G001, S005
S007 · implies
操作前
source roles = [[[0, -19, 1], [1, -19, 20], [2, 20, 3], [3, 1017, 0]], 1017, 0, 24]
操作後
derived = [0/1]
條件:無
空fiber依空和0得到0/1;否則逐項加總再除原den。約分與正分母不改事件,整數機率仍顯示/1。
步驟識別與依賴
規則:RV_point_mass_unattained_value_zero_and_reduced_fraction · 依賴:G001, S006