A company wanted to know if attending a course on "how to be a successful salesperson" can increase the 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 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 the mean of the 6 differences
2. Find the standard deviation of the differences
3. To find out whether the course is effective in increasing sales, the appropriate set of hypothesis for testing is (Be careful which one you choose!)
a. H0: μ = 0, Ha: μ < 0
b. H0: μ = 0, Ha: μ ≠ 0
c. H0: μ = 0, Ha: μ > 0
4. The appropriate test to use is
a. TTest b. 1-PropZtest c. ZTest d. Chi-square test
5. Write down the p-value of the test
6. Based on the p-value and α = 0.05, the null hypothesis (Ho) is
a. Rejected b. not rejected c. Not enough information to draw a conclusion
7. Based on the above analysis (p-value and α = 0.05), we conclude that the course is
a. effective
b. not effective
c. Not enough information to draw a conclusion