

Bayes theorem
Ex 13.3, 2 Important
Ex 13.3, 3
Misc 3 You are here
Ex 13.3, 4 Important
Ex 13.3, 9
Ex 13.3, 5
Ex 13.3, 13 (MCQ) Important
Example 21 Important
Ex 13.3, 6 Important
Ex 13.3, 10 Important
Example 18 Important
Example 17 Important
Ex 13.3, 7
Ex 13.3, 8 Important
Example 19 Important
Ex 13.3, 11
Ex 13.3, 12 Important
Example 37 Important
Example 20 Important
Example 33 Important
Misc 12
Misc 16 Important
Misc 13 Important
Bayes theorem
Misc 3 Suppose that 5% of men and 0.25% of women have grey hair. A grey haired person is selected at random. What is the probability of this person being male? Assume that there are equal number of males and females. Let M : Male F : Female G : Grey hair Person We need to find the Probability that the person selected is male, if the person is grey haired i.e. P(M|G) P(M|G) = . ( | ) . | + . ( | ) Putting value in formula, P(M|G) = 0. 5 0 . 05 0. 5 0. 0025 + 0. 5 0. 05 = 0. 5 0 . 05 0. 5 0. 0025 + 0. 05 = 0.05 0.0525 = 500 525 = Therefore, required probability is 20 21