There is conflicting information about whether a new medication affects a person's ability to concentrate as measured by time spent on a task.

You wish to test the following claim (H_a) at a significance level of a = 0.01. For the context of this problem, u_d = u_{2 -} u₁ where the first data set represents a pre-test measure of time on task and the second data set represents a post-test measure of time on task.

H_o : u_d = 0

H_a : u_d < 0

You believe the population of difference scores is normally distributed, but you do not know the standard deviation. You obtain the following sample of data:

Pre-test ++++++++ Post-test

67.7 ++++++++++++ 49.9

45.9 ++++++++++++ 29.9

35.9 ++++++++++++ 46.4

73.7 ++++++++++++ 95.5

72.3 ++++++++++++ 56.8

49.9 ++++++++++++ 36.4

58.5 ++++++++++++ 57.9

52.2 ++++++++++++ 41.4

What is the test statistic for this simple? (report answer accurate to 3 decimal places)

test statistic = ___________

What is the p-value for this sample? (Report answer accurate for 4 decimal places)

p-value = ____________

The p-value is:

a. less than (or equal to) a

b. greater than a

This test statistic leads to a decision to:

a. Reject the null

b. Accept the null

c. Fail to reject the null

As such. the final conclusion is that:

a. There is sufficient evidence to warrant rejection of the claim that the mean difference of post-test from pre-test is less than 0.

b. There is not sufficient evidence to warrant rejection of the claim that the mean difference of post-test from pre-test is less than 0.

c. The sample data support the claim that the mean difference of post-test from pre-test is less than 0.

d. There is not sufficient sample evidence to support the claim that the mean difference of post-test from pre-test is less than 0.