Hypothesis testig for paired sample t test.
A company wanted to know if attending a course on "how to be a successful salesperson" can increase average sales of its employees. The company sent six of its salespersons to attend this course. The following table gives the one-week sales of these salespersons before and after they attended this course:
|
Before
|
12
|
18
|
25
|
9
|
14
|
16
|
|
After
|
18
|
24
|
24
|
14
|
19
|
20
|
|
Differences
|
|
|
|
|
|
|
First find out the 6 differences (Before course sales - After course sales)
|
Before
|
12
|
18
|
25
|
9
|
14
|
16
|
|
After
|
18
|
24
|
24
|
14
|
19
|
20
|
|
Differences
|
-6
|
-6
|
1
|
-5
|
-5
|
-4
|
Where,
Differences = before course sales - After course sales
1. Find out the mean of the 6 differences
2. Find out the standard deviation of the differences
3. To find out whether the course is effective in increasing sale, the appropriate set of hypothesis for testing is (Be careful which one you choose!)
4. The appropriate test to use is
a. T-test b. 1-PropZtest c. ZTest d. Chi-square test