What would be the value of z for a 97.5% confidence interval for the population proportion?

What value of t would you use for a 90% confidence interval for the population mean when the sample size was equal to 15?

Suppose that 1/6 of all Americans have blue eyes. We take a random sample of 100 and find that 20 have blue eyes. What would be the mean of the sampling distribution of the sample proportion?

In the year 2015, according to salary.com, nurses in Los Angelos have an average annual salary of $85,693. The standard deviation is about 6,000 dollars. The distribution of salaries is right skewed. Suppose that a sample of 100 nurses is taken from Los Angelos. What is the approximate sampling distribution of the sample mean?  

Fifteen females were recorded on their reaction time to a stimulus. The 95% confidence interval for the population mean was (14.56, 18.75) seconds. What do we know from this confidence interval?

Suppose the sampling distribution for average weight for NFL players is normally distributed with a mean of 246.9 pounds and a standard error of 7 pounds.  Find the range of central 95% of sample means.

In the United States, 30% of all Americans have a college degree. Suppose that your friend took a random sample of 100 people and found that 34% of the sample had a college degree.  Match the following terms.

The average height of men in Cameroon is 1.706 meters with a standard deviation of 0.154 m. Height is approximately normally distributed. Suppose that a sample of 35 men is selected, find the range of the central 95% of sample mean heights?

A survey of 30 randomly selected people from Gainesville were asked if they planned on moving in the next year. Out of 30 people, 12 said yes. Can you make a 95% confidence interval for the population proportion?

If n is decreased, what happens to the standard error of the sampling distribution of the sample mean?