Question

Questions 8 and 9 are based on the following information:

A local retail business wishes to determine if there is a difference in the mean preferred indoor temperature between men and women. Assume that the population standard deviations of pre- ferred temperatures are equal between men and women. Two independent random samples are collected. Sample statistics of preferred temperatures are reported in the table below.

	Sample Size	Mean (In Celsius)
Men (Group 1)	25	22.5
Women (Group 2)	22	20.1

Standard deviation : Men: 1.2. Women : 1.4

In testing whether two population means are different, the value of test statistic is .

A. 1.255

B. 1.378

C. 1.405

D. 1.578

Suppose that we perform a two-tailed test of the difference of population means, which of the following is the correct conclusion?

A. At the 0.20 significance level, we reject the null hypothesis, there is a difference in the preferred indoor temperature between men and women.

B. At the 0.10 significance level, we reject the null hypothesis, there is a difference in the preferred indoor temperature between men and women.

C. At the 0.10 significance level, we fail to reject the null hypothesis, since the test statistic is smaller than the critical value 1.645.

D. There is in sufficient evidence to draw a conclusion on the test.

Answer 1

using excel>addin>phstat>two sample t

we have

Pooled-Variance t Test for the Difference Between Two Means
(assumes equal population variances)
Data
Hypothesized Difference	0
Level of Significance	0.05
Population 1 Sample
Sample Size	25
Sample Mean	22.5
Sample Standard Deviation	1.2
Population 2 Sample
Sample Size	22
Sample Mean	20.1
Sample Standard Deviation	1.4
Intermediate Calculations
Population 1 Sample Degrees of Freedom	24
Population 2 Sample Degrees of Freedom	21
Total Degrees of Freedom	45
Pooled Variance	1.6827
Standard Error	0.3792
Difference in Sample Means	2.4000
t Test Statistic	6.3291
Two-Tail Test
Lower Critical Value	-2.0141
Upper Critical Value	2.0141
p-Value	0.0000
Reject the null hypothesis

the value of test statistic is .6.3291 which is not given in the answers so all the answers are wrong .

option a and b is true

A. At the 0.20 significance level, we reject the null hypothesis, there is a difference in the preferred indoor temperature between men and women.

B. At the 0.10 significance level, we reject the null hypothesis, there is a difference in the preferred indoor temperature between men and women.