Find the critical val. ($t_{\alpha \text{⁄}2}$) for each confidence interval.
(B) Confidence Level = $90\%,n=48$

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.

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 each probability.

(A) $P(T>1.5),df=8$

Find each probability.

(B)

A nutritionist wants to estimate the average grams of protein in a brand of protein bars. She takes a random sample of 40 protein bars with $\bar{x}=210$ g & knows from prior data that $\sigma =12$. Make a 95% conf. int. for $\mu$.

A company wants to estimate the average time employees spend on a training module. 15 employees are randomly selected, & their completion times recorded. The sample of times to complete the module is normally distributed with mean 42.7 min & std. dev. 5.4 min.

(A) Make a 95% conf. int. for the true mean time to complete the training.