Sample Size Sample Mean Population Standard Deviation Men 25

Sample Size

Sample Mean

Population Standard
Deviation

Men

25

20

5

Women

30

30

10

At the .01 significance level, is there a difference in the mean number of times men and women in a day? What is the test statistic for this hypothesis?

Solution

H0: There is no difference in the average for men and women Or mu1 - mu2 =0

Ha: there is difference.

Two tailed test for comparison of two sample means.

t test only can be used as sample size of I group <30

The mean of Group One minus Group Two equals -10.00
  95% confidence interval of this difference: From -14.41 to -5.59

t statistic = 4.5442

df = 53

Std error of differnce = 2.201

p value = 0.000001

As p value is < 0.01 reject null hypothesis.

By conventional criteria, this difference is considered to be extremely statistically significant.