1.Calculate the pooled variance for the following examples.

a.Sample 1: SS = 1,894n = 124Sample 2: SS = 1,467n = 178

b.Sample 1: SS = 539n = 78Sample 2: SS = 467df = 56

2.Calculate the estimated standard error using the same examples.

a.Sample 1: SS = 1,894n = 124Sample 2: SS = 1,467n = 178

b.Sample 1: SS = 539n = 78Sample 2: SS = 467df = 56

3.Harper's clothing store wants to evaluate which is the most efficient way to have customers check out. Is it better to have customers line up behind individual registers or make a single file snake line in which they go to the next available register. They conduct two samples, each with 14 days. With the help of a statistician they have obtained the following information. Using an alpha of .05, help them answer the following questions.

Individual lines: M = 47 customers per hourSS = 783

Single line: M = 41 customers per hourSS = 613

a.Write out their null and alternative hypotheses.

b.What is their t-critical value(s)?

c.What is the pooled variance?

d.Compute the estimated standard error and t-statistic.

e.Make a decision regarding the null and provide a conclusion in proper notation.

4.Construct a confidence interval and state a conclusion (Reject H_o, Fail to Reject H_o) for the following examples.

a.Est std err = 3.5Sample 1: M = 163n = 124Sample 2: M = 150n = 178

Construct a 95% confidence interval with a two-tailed hypothesis

b.Est std err = 0.11Sample 1: M = 3.2n = 24Sample 2: M = 3.4n = 15

Construct a 99% confidence interval with a two-tailed hypothesis

5.What is our t-critical value(s) if our samples have 12 and 19 people, we want to use an alpha of .01, and do not have hypotheses which include direction?