Question

The Insurance company recently conducted an aggressive and expensive advertising campaign. The manager is trying to figure out how this campaign affected branch’s profits. The branch manager is pretty skeptical about the campaign and asked you to check whether there was any significant influence (positive or, maybe, negative). A sample is randomly selected of sales reps and calculated monthly combined profits of the policies sold by them before and after the advertising campaign. The sample is small, but as far as all conditions are satisfied we can use t-test for matched pairs. See the data in the data file. Provide Excel output.

    

1. Write the null and alternative hypotheses for this test using d = Before ─ After:
2. What is the value of the t-test statistic?
3. What is the associated P-value?
4. State the conclusion using α = 0.02. Do it using both P-value and critical value.

	Before	After
1	$3,487.00	$4,350.00
2	$7,500.50	$6,400.00
3	$2,500.85	$3,209.95
4	$6,990.75	$6,775.75
5	$4,192.00	$3,990.50
6	$7,580.25	$7,265.70
7	$10,750.00	$11,755.45
8	$4,411.00	$3,890.75
9	$7,945.50	$7,550.50
10	$4,575.85	$5,010.65

Answer 1

	Before	After	Difference = Before - After
	3487	4350	-863
	7500.5	6400	1100.5
	2500.85	3209.95	-709.1
	6990.75	6775.75	215
	4192	3990.5	201.5
	7580.25	7265.7	314.55
	10750	11755.45	-1005.45
	4411	3890.75	520.25
	7945.5	7550.5	395
	4575.85	5010.65	-434.8
Average	5993.37	6019.925	-26.555
St. Dev.	2548.606	2535.565	688.321
n	10	10	10

You have a critical and P-value conclusion in c. overall conclusion in d. Don't get confused