1. Are the following samples independent or dependent (paired)?

As part of a marketing experiment, a department store regularly mailed discount coupons to 25 of its credit card holders. Their total credit card purchases over the next three months were compared to the credit card purchases over the next three months for 25 credit card holders who were not sent discount coupons. Determine whether the samples are dependent or independent.

A) dependent

B) independent

2. When the variances of two populations are equal and we are performing a t-test for the difference between two means, we:

A) Do not change our calculations based on the equal variances

B) Use a pooled estimate for the standard deviation

C) Do not use a pooled estimate for the standard deviation

For the following hypothesis testing questions, you may use either the p-value method or the rejection region method. For full credit, be sure to show:

The null and alternative hypotheses

The p-value or test statistic/rejection region (depending on method used)

The decision (reject H0 or fail to reject H0)

The interpretation

3. In an effort to determine if rats perform certain tasks more quickly if offered larger rewards, the following experiment was performed. On day 1, a group of six rats was given a reward of one food pellet each time they ran a maze. On day 2, the same group of rats received five food pellets each time they ran a maze. The average time in seconds for each rat to run the maze is shown

Rat	1	2	3	4	5	6
Time with one food pellet	3.6	4.2	2.9	3.1	3.5	3.9
Time with five food pellets	3.0	3.7	3.0	3.3	2.8	3.0

Test the claim that rats will run the maze more quickly if offered a larger reward. Use a significance level of 0.05. (Hint: consider the units, if they run faster will the mean time be larger or smaller?)

4. A researcher is studying the SAT 1 Math scores of two groups of students: those who plan to apply for financial aid and those that do not. Two independent random samples yield the following:

Do not plan to apply for financial aid	Plan to apply for financial aid
n 1 =35	n2= 38
s1= 123.1	s2=119.4
(Please note that bar is supposed to be over X but I could not figure out how to do it here) x1= 450	(Please note that bar is supposed to be over X but I could not figure out how to do it here) x2=480