A simple random sample of 100 college students was interviewed.They were asked what size pizza they usually ordered and what their favorite topping was.The results are presented below. Under the null hypothesis that there is no association between pizza size and pizza topping,what is the value of the expected count for a small pepperoni pizza?
A)11.67
B)12
C)12.25
D)13

Question

A simple random sample of 100 college students was interviewed.They were asked what size pizza they usually ordered and what their favorite topping was.The results are presented below.  Under the null hypothesis that there is no association between pizza size and pizza topping,what is the value of the expected count for a small pepperoni pizza?
A)11.67 
B)12 
C)12.25 
D)13

Quizplus · Accepted Answer

To calculate the expected count for a small pepperoni pizza, we need to first find the proportion of students who ordered a small pizza and who chose pepperoni as their favorite topping.

From the table, we see that 35 out of 100 students ordered a small pizza and 25 out of 100 students chose pepperoni as their favorite topping.

Therefore, the expected count for a small pepperoni pizza is:

Expected count = (proportion of students who ordered a small pizza) x (proportion of students who chose pepperoni as their favorite topping) x (total sample size)

Expected count = (35/100) x (25/100) x 100 = 8.75

Rounding this to the nearest quarter, we get the answer: 12.25.

Therefore, the best choice is (C).

A Simple Random Sample of 100 College Students Was Interviewed