Question

Question 1:

Suppose we are testing the effectiveness of a new hypnosis treatment at reducing cigarette smoking. 20 smokers are recruited. Half are randomly assigned to a control treatment where they are given some information about the dangers of smoking and sent home. The other half receives the new hypnosis treatment. Four weeks later we measure the number of cigarettes each participant smokes in a week. We want to see if people who receive the treatment smoke a different average number of cigarettes after 4 weeks than those who don’t.

Only use the column labeled "Group" and the column labeled "Cigarettes" for this question. Ignore the other columns for now.

Calculate the t statistic for testing the null hypothesis that there is no difference in mean cigarettes smoked between the two conditions with a 2-tailed test using an α=.05

Use Control - Treatment to calculate t and type in only the numeric value of t. Don't include any letters or symbols in your answer (other than a sign or decimal point if appropriate). Give at least 2 places past the decimal point.

Participant	Group	Cigarettes
1	Control	7
2	Control	9
3	Control	6
4	Control	9
5	Control	5
6	Control	7
7	Control	8
8	Control	7
9	Control	11
10	Control	6
1	Treatment	6
2	Treatment	7
3	Treatment	5
4	Treatment	6
5	Treatment	3
6	Treatment	5
7	Treatment	5
8	Treatment	8
9	Treatment	9
10	Treatment	6

Question 2:

Calculate the 2-tailed probability value for the t you found in question 1.

Don't include any letters or symbols (other than a sign or decimal point if appropriate). Give at least 3 places past the decimal point.

Question 3:

Which of the following can you conclude based on the probability value you found in question 2?

Answer Options:

A.) Accept H₀, there is no difference in the average number of cigarettes smoked by the two groups

B.) Reject the H₀, the control group smokes fewer cigarettes than the treatment group.

C.) Do not reject the H₀, We cannot say whether the groups smoke a different amount on average or not

D.) Reject the H₀, there is no difference in the average number of cigarettes smoked by the two groups

Answer 1