For this case we have that the cost of each pizza is given by the following function:

Where:
r: It's the radius of the pizza
IF a pizza cost $26.32 we have:

We cleared the radius, using
:

We choose the positive value:

So, the radius of the pizza is 
Then, the diameter is: 
Finally, the diameter of the pizza is:
Answer:
Option B
Answer:
Step-by-step explanation:
Givens
Number not using given app = 71
Total number of students = 219
% = ?
Solution
P(~given app) = 71 / 219
P(~given app) = 0.324
% = 0.324 * 100 = 32.4%
Answer
32.4% do not use Given App