Question

A high school baseball player has a 0.215 batting average. In one game, he gets 7 at bats. What is the probability he will get at least 5 hits in the game?

Answer 1

0.651%

Explanation:

using Binomial expansion: nCr*p^n*(1-p)^(n-r)

probability he will get at least 5 hits in the game = probability he will get 5 hits in the game + probability he will get 6 hits in the game + probability he will get 7 hits in the game = 7C5*0.215^5*(1-0.215)^2 + 7C6*0.215^6*(1-0.215)^1 +7C7*0.215^7*(1-0.215)^0 = 21* 0.0004594*0.616225 + 7*0.00009877*0.785 + 1*0.000021235 = 0.00651 = 0.651%