A cognitive researcher wants to know what effect alcohol consumption has on speed of mental processing. He asks 10 subjects to answer a simple addition equation, and times how long it takes them to answer (in seconds). He firsts asks them a question before they consume any alcohol, and then again after they consume two drinks containing 1 ounces of liquor each. The subjects' data are presented below. Find out if alcohol impacted subjects' speed of answering.

Subject Before drinking After two drinks Difference

1 2 6 -4

2 1 4 -3

3 4 5 -1

4 3 7 -4

5 1 5 -4

6 2 5 -3

7 3 6 -3

8 3 8 -5

9 2 4 -2

10 3 2 -1

D=-30

(a) What type of t-test should be used?

(b) What is null and alternative hypotheses

(c) What is df AND critical values of t, with =.05; assume a two-tailed test

(d) Calculate t

(e) State whether or not the null hypothesis should be rejected

(f) Give a brief sentence summarizing the outcome of this null hypothesis test in terms of the research question