You want to take a trip to Paris. You randomly select 225 flights to Europe and find a mean and sample standard deviation of \$1500 and \$900, respectively. Construct and interpret a 95% confidence interval for the true mean price for a trip to Paris.

Find the critical value $t_{\frac{\alpha}{2}}$for an 80% confidence interval given a sample size of 51.

Find the critical value $t_{\frac{\alpha}{2}}$for a 95% confidence interval given a sample size of 6.

For which of the following scenarios can you NOT create a confidence interval using the standard normal or Student t-distribution?

You ask 16 people in your Statistics class what their grade is. The data appears to be distributed normally. You find a sample mean and sample standard deviation of 60 and 24, respectively. Construct and interpret a 95% confidence interval for the population mean class grade.

You want to purchase one of the new Altimas. You randomly select 400 dealerships across the United States and find a mean of \$25,000 and sample standard deviation of \$2500. Construct and interpret a 94% confidence interval for the true mean price for the new Nissan Altima.

Fill out the table using a calculator and $n=30$.

Find the critical val. ($t_{\alpha \text{⁄}2}$) for each confidence interval.

(A) Confidence Level = $95\%,n=35$

Find the critical val. ($t_{\alpha \text{⁄}2}$) for each confidence interval.

(B) Confidence Level = $90\%,n=48$