Question

The following table contains information on matched sample values whose differences are normally distributed. (You may find it useful to reference the appropriate table: z table or t table)

Number Sample 1 Sample 2

1 18 22

2 13 11

3 22 23

4 23 20

5 17 21

6 14 16

7 18 18

8 19 20

Construct the 99% confidence interval for the mean difference μD. (Negative values should be indicated by a minus sign. Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

Answer 1

The statistical software output for this problem is :

Paired T confidence interval:
μ_D = μ₁ - μ₂ : Mean of the difference between 1 and 2
99% confidence interval results:

Difference	Mean	Std. Err.	DF	L. Limit	U. Limit
1 - 2	-0.875	0.89517556	7	-4.0076519	2.2576519

The 99% confidence interval for the mean difference μD is :

(-4.01 , 2.26)