Question

10-10. 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

a. Construct the 99% confidence interval for the mean difference μ_D. (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.)

Confidence interval is_______ to______.

b. Specify the competing hypotheses in order to test whether the mean difference differs from zero.

• H₀: μ_D ≥ 0; H_A: μ_D < 0

• H₀: μ_D = 0; H_A: μ_D ≠ 0

• H₀: μ_D ≤ 0; H_A: μ_D > 0

c. Using the confidence interval from part a, are you able to reject H₀?

• Yes

• No

d. Interpret the results at αα = 0.01.

• We conclude that the mean difference differs from zero.

• We cannot conclude that the mean difference differs from zero.

• We conclude that population mean 2 is greater than population mean 1.

• We cannot conclude that population mean 2 is greater than population mean 1.

Answer 1