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

Suppose the proportion of Americans with lupus is 0.004. You take a random sample of 4000 people and ask them if they have the disease. What approximate distribution would you expect for the sampling distribution of the sample proportion of Americans who have the disease?

In 2012, the General Social Survey asked its respondents if they had volunteered in the past month. The 95% confidence interval for this result was (0.313, 0.378). Is the following a correct or incorrect interpretation statement? “The probability that the sample proportion is between 0.313 and .378 is 0.95.”

Suppose the sampling distribution for average height for NFL players is normally distributed with a mean of 74 and a standard error of 2 inches.  Find the range of central 99.7% of sample means.

Suppose the sampling distribution for average height for NFL players is normally distributed with a mean of 74 and a standard error of 2 inches.  Find the range of central 95% of sample means.

The amount of calories in a small serving of French Fries at McDonalds is Normally distributed with a mean of 230 calories and a standard deviation of 15. Suppose that a random sample of 10 small servings was collected. What is the probability that the sample mean is greater than 240 calories?

What is the standard error of the sampling distribution of the sample mean?

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. The distribution of salaries is right skewed. Suppose that a sample of 10 physical therapists is taken from Jacksonville, Florida. What is the sampling distribution of the sample mean?  

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 0.025 margin of error. Find the sample size needed.

A random sample of students were asked how many hours they exercised each week. The research was interested in estimating the population standard deviation. Below are the results of bootstrapping the standard deviation. What is the 95% confidence interval for the population standard deviation using the bootstrap method?