Find the value of t for a 90% confidence interval for the population mean when n = 19.

The Queensland male koala has an average weight of 6.5kg. Male Koalas weights are normally distributed with a standard deviation of 0.82. Suppose that 5 randomly selected koalas were selected. What is the sampling distribution of the sample mean?

Suppose that 60% of Americans planned to vote in the next election. You take a random sample of 100 people and ask them if they plan on voting in the next presidential election.  What approximate distribution would you expect for the sampling distribution of the sample proportion of Americans who planned on voting?

Suppose the sampling distribution for average weight for soccer players is normally distributed with a mean of 152 pounds and a standard error of 5.  Find the range of central 95% of sample means.

Suppose the sampling distribution for average calories in bananas is normally distributed with a mean of 105 and a standard error of 4.  Find the range of central 99.7% of sample means.

Which of the following is a property of the t distribution?

In the year 2014, according to salary.com, physical therapists in Jacksonville, Florida have an average annual salary of 75,000. The standard deviation is about 6,000 dollars. Suppose that a sample of 15 physical therapists is taken from Jacksonville, Florida. What is the sampling distribution of the sample mean?  

In the 2012 presidential election, 57.5% of eligible voters cast their vote. Suppose that 200 randomly selected eligible voters were asked if they had voted in the 2012 presidential election. What approximate distribution would you expect for the sampling distribution of the sample proportion of Americans who voted in the 2012 presidential election?  

Suppose that you were interested in conducting a survey of Floridians and asking if they approved of the President. Suppose that you have no idea what this proportion would be, but at the end of the study you want to calculate a 95% confidence interval with a 0.045 margin of error. Find the sample size needed.

For a 95% confidence interval for the population mean, what value of t would you use? n = 15