SOLUTION: The Pizza Shop wanted to determine what proportion of its customers ordered only cheese pizza. Out of 80 customers surveyed, 15 ordered cheese pizza. What is the 99% confidence int

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Question 479410: The Pizza Shop wanted to determine what proportion of its customers ordered only cheese pizza. Out of 80 customers surveyed, 15 ordered cheese pizza. What is the 99% confidence interval of the true proportion of customers who order only cheese pizza?
Answer by edjones(7569) About Me  (Show Source):
You can put this solution on YOUR website!
p=15/80=.1875, q=.8125,
sigma=sqrt%28%28.1875%2A.8125%29%2F80%29=.0436
(a,b)=.1875 +-(2.576*.0436) [2.576 is the area under the normal curve for the 99% confidence level.]
=.1875 +-.1123
=(.2998, .0752) the 99% confidence interval of the true proportion of customers who order only cheese pizza.