Question

Four males with X-linked genetic disorder have one child each. The random variable x is the number of children among the four who inherit the X-linked genetic disorder.

X 0 1 2 3 4
P(X) 0.04 0.26 0.45 0.20 0.05

What is the probability that exactly two children inherited the X-linked genetic disorder?

Answer 1

45% probability that exactly two children inherited the X-linked genetic disorder.

Explanation:

X assumes values 0,1,2,3,4

P(0) = 0.04

P(1) = 0.26

P(2) = 0.45

P(3) = 0.2

P(4) = 0.05

This is our probability distribution

The probability distribution that we have in this problem means that:

4% probability that no children inherited the X-linked genetic disorder.

26% probability that exactly one children inherited the X-linked genetic disorder

45% probability that exactly two children inherited the X-linked genetic disorder.

20% probability that exactly three children inherited the X-linked genetic disorder

5% probability that all four children inherited the X-linked genetic disorder

What is the probability that exactly two children inherited the X-linked genetic disorder?

45%