1.Determine the t-value in each of the cases.

(a) Find the t-value such that the area in the right tail is 0.025 with 26 degrees of freedom._________ (Round to three decimal places as needed.)

(b) Find the t-value such that the area in the right tail is 0.15 with 27 degrees of freedom.________ (Round to three decimal places as needed.)

(c) Find the t-value such that the area left of the t-value is 0.05 with 5 degrees of freedom. [Hint: Use symmetry.]_______(Round to three decimal places.)

(d) Find the critical t-value that corresponds to 80% confidence. Assume 11 degrees of freedom._______ (Round to three decimal places as needed.)

2. A trade magazine routinely checks the drive-through service times of fast-food restaurants. A 95% confidence interval that results from examining 615 customers in one fast-food chain's drive-through has a lower bound of 171.9 seconds and an upper bound of 175.3 seconds.

What does this mean?

A. There is a____% probability that the mean drive-through service time of this fast-food chain is between ____seconds and ______ seconds.

B. One can be____% confident that the mean drive-through service time of this fast-food chain is______ seconds.

C. One can be _____% confident that the mean drive-through service time of this fast-food chain is between ___ seconds and _____seconds.

D. The mean drive-through service time of this fast-food chain is _____ seconds _______% of the time.

3. Construct a confidence interval for p1p2 at the given level of confidence. x1=33, n1=254, x2=36, n2=291, 95% confidence

The researchers are____% confident the difference between the two population proportions, p1p2, is between____ and___

(An integer or decimal rounded to three decimal places as needed.)