Question

A college looked at a random sample of students who worked the previous summer.  

Use the following information to answer questions 1 - 7.

The following data show the average earnings and sample standard deviations for a random sample of males and a random sample of females.

Group	n	x̄	s
males	15	3400	2495
females	20	2500	1920

The following degrees of freedom may be helpful: 25.49

1) Find the point estimate of the difference between the mean summer earnings for males and the mean summer earnings for females.

2) Find the 95% confidence interval for the difference between the means of the two populations.

3) The college is interested in showing that the mean summer earnings for the males is greater than the mean summer earnings for females. What null and alternate hypothesis should the college use?

4) The college is interested in showing that the mean summer earnings for males is greater than the mean summer earnings for females. What is the value of the test statistic?
a) 3.17
b) -3.17
c) 2.10
d) -2.10
e) 1.16
f) -1.16
g) none of the above

5) The null hypothesis in problem 3 is to be tested at the 5% level of significance. The rejection region (regions) from the table is (are):
a)           z≤-1.96 or z≥1.96
b)           z≤1.96
c)            z≤-1.96
d)            z≤-1.645 or z≥1.645
e)            t≥1.708
f)            t≤-1.708
g)            t≤-1.708or t≥1.708
h)            t≤-2.060
i)             t≥2.060
j)             t≤-2.060 or t≥2.060

6) If the null hypothesis is tested in problem 4 at the 5% level, the null hypothesis should be:
a) rejected
b) not rejected
c) impossible to determine

7) Find the p-value for the hypothesis test in problem 4.
a) p-value>.10
b) .05 c) .025 d) .01 e) .005 f) p-value<.005

Steps on how to get the answers would be appreciated. Thanks.

Answer 1