Question

Ms. Lisa Monnin is the budget director for Nexus Media Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.

Sales ($)	127	137	140	159	136	138
Audit ($)	123	102	128	143	153	127	131

At the 0.050 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff?

a. State the decision rule.

b. Compute the pooled estimate of the population variance. (Round your answer to 2 decimal places.)

c. Compute the test statistic. (Round your answer to 3 decimal places.)

Answer 1

Excel : Data - Data analysis - t-Test: Two-Sample Assuming Equal Variances

Sales ($)	127	137	140	159	136	138
Audit ($)	123	102	128	143	153	127	131
t-Test: Two-Sample Assuming Equal Variances
	Variable 1	Variable 2
Mean	139.5	129.5714
Variance	111.5	257.2857
Observations	6	7
Pooled Variance	191.0195
Hypothesized Mean Difference	0
df	11
t Stat	1.291222
P(T<=t) one-tail	0.111551
t Critical one-tail	1.795885
P(T<=t) two-tail	0.223101
t Critical two-tail	2.200985

(a) Reject H0 if t > 1.796

(b)

Pooled Variance

191.02

(c)

t Stat

1.291