Question

Question 1:

Let's say that instead of recruiting 20 smokers and assigning them each to one condition, we decided to try to minimize our error variance by recruiting 10 smokers, measuring how much they smoke in a week before the hypnosis treatment, then conducting the treatment and measuring them again after. Use the data from Question 1, only now take note of the "Participant" column in addition to the "Group" and "Cigarettes" columns. You can see that you have a control score and a treatment score for each participant.

Calculate a t statistic for testing the null hypothesis that, on average, there is no change in the number of cigarettes people smoke before and after the treatment. Use a 2-tailed test with an α=.05

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:

What is the probability value for the t statistic you calculated in the previous question?

Report the 2-tailed probability value to 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 the previous question?

Answer Options:

A.) Reject the H₀, people smoke fewer cigarettes on average after the treatment than before it.

B.) Reject the H₀, there is no difference in the average number of cigarettes smoked before and after treatment

C.) Reject the H₀, people smoke fewer cigarettes on average before the treatment than after it.

D.) Do not reject the H₀, We cannot say whether or not the amount people smoke is affected by the treatment

E.) Accept H₀, there is no difference in the average number of cigarettes smoked before and after treatment.

Answer 1

1)

t statistic =3.74

2)

probability value for the t statistic you calculated in the previous question =0.0046

3)

A.) Reject the H₀, people smoke fewer cigarettes on average after the treatment than before it.