Question

A tennis player makes a successful first serve​ 51% of the time. If she serves 9​ times, what is the probability that she gets exactly 3 successful first serves​ in? Assume that each serve is independent of the others.

Answer 1

Answer:0.154

Explanation:

Given

Probability of success p=0.51

Probability of failure q=0.49

She serves 9 times out which she gets exactly 3 successful first serves in

Using binomial distribution to find Probability of exactly r successful attempts out of n is given by

$^nC_r(p)^r(q)^{n-r}$

For r=3 and n=9

$=^9C_3(0.51)^{3}(0.49)^{6}$

$=84\times 0.00183606=0.1542$