11	The Mission College Health Service wanted to know the proportion of Mission College students who have had a flu shot. A sample of 200 students showed that 120 had a flu shot. Create a confidence interval at 95% confidence for the proportion of all Mission College students who have a flu shot.
12	The weight ofthe contents of a type of box of cereal is normally distributed with population mean = 30 ounces and population standard deviation = 3.2 ounces. A random sample (size n = 25) is taken. What is the probability that the sample mean () is less than 31.74 ounces?
13	A manufacturer of personal computers wants to estimate the population mean for the useful life of the computers. A random sample of 100 computers shows a sample mean= 4000 hours with a sample standard deviation s = 50 hours. Create a confidence interval at 99% confidence for the population mean.
14	A political scientist wants to estimate the proportion of registered voters who actually vote. A random sample of 400 voters showed that 250 voted. Create a confidence limit at 90% confidence for the proportion of all voters who vote.
15	A medical center wants to determine the mean duration of human pregnancy. A sample of 49 pregnancies showed a sample mean= 282 days with sample standard deviation s = 12 days. Create a confidence interval at 90% confidence for the population mean.
16	A medical researcher wants to determine the proportion of people with migraine headaches who are helped by a new drug. A random sample of 150 people with migraine headaches shows that 100 are helped. Create a confidence interval at 95% confidence for the proportion of all people with migraines who are helped.