Conditional Probability - Values given
Last updated at Dec. 16, 2024 by Teachoo
Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (i) P(A ∩ B)Given P(A) = 0.8 , P(B) = 0.5 & P(B|A) = 0.4 Now, P(B|A) = (𝑃(𝐵 ∩ 𝐴))/(𝑃(𝐴)) 0.4 = (𝑷(𝑨 ∩ 𝑩))/(𝟎. 𝟖) P(A ∩ B) = 0.4 × 0.8 P(A ∩ B) = 0.32 Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (ii) P(A|B)P(A|B) = (𝑃(𝐴 ∩ 𝐵))/(𝑃(𝐵)) = (𝟎.𝟑𝟐)/(𝟎.𝟓) = 32/50 = 0.64 Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (iii) P(A ∪ B)P(A ∪ B) = P(A) + P(B) – P(A ∩ B) = 0.8 + 0.5 – 0.32 = 1.3 – 0.32 = 0.98