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 (HaHa) at a significance level of α=0.001α=0.001. For the context of this problem, μd=μ2-μ1μd=μ2-μ1 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.
Ho:μd=0Ho:μd=0
Ha:μd<0Ha:μd<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
54.3 49.2
46.4 28.2
57.6 17.5
48.6 21.8
39 -9.5
39.4 38.8
46.8 42.1
43.7 44.3
What is the test statistic for this sample? (Report answer accurate to three decimal places.)
test statistic =
What is the p-value for this sample? (Report answer accurate to four decimal places.)
p-value =
The p-value is...
- less than (or equal to) αα
- greater than αα
This test statistic leads to a decision to...
- reject the null
- accept the null
- fail to reject the null
As such, the final conclusion is that...
- There is sufficient evidence to warrant rejection of the claim that the mean difference of post-test from pre-test is less than 0.
- 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.
- The sample data support the claim that the mean difference of post-test from pre-test is less than 0.
- There is not sufficient sample evidence to support the claim that the mean difference of post-test from pre-test is less than 0.