Question

The probability that Roberto throws a baseball in the strike zone on one pitch is 0.72. Roberto throws a baseball 3 times in a row.
A. Create a probability distribution for X, the number of times Roberto throws the baseball in the strike zone. Show how you obtained each probability. Round each probability to three decimal places.

Answer 1

I actually just finished this assignment: 

These are binomials with n = 3 and p = 0.72

P(X=0) = 3C0 (0.72^0)(0.28^3) = 0.022
P(X=1) = 3C0 (0.72^1)(0.28^2) = 0.169
P(X=2) = 3C0 (0.72^2)(0.28^1) = 0.435
P(X=3) = 3C0 (0.72^3)(0.28^0) = 0.373 

Notice how they all equal 1.