In a study of monthly salary distribution of residents in Paris conducted in year 2015, it was

found that the salaries had an average of 2200 (EURO) and a standard deviation of 550.

One years later (in 2016), it was suspected that the average salary had increased. A hypothesis

test was conducted at a significance level of 5% to test the suspicion. A random sample of size

64 was chosen with mean of 2385 and standard deviation of 650.

In another study conducted in 2016, the average of monthly salaries of 45 randomly chosen

residents in Bordeaux was found to be 3200; the sample standard deviation of the chosen

salaries was 600. The suspicion was that the average salary of residents in Paris is lower than

the average salary of residents in Bordeaux.

The research team was to conduct a -test to test the suspicion. But they had no information on

the two population variances. So they first conducted an -test at a significance level of 5% to

determine if the two population variances are equal or not, assuming that both populations were

normal.

Set 1 = Paris; 2 = Bordeaux.

Set up the alternative hypothesis for the -test.

Question 9:

In the -test, what is the test statistic?

Question 10:

Find the rejection region in the -test.

Question 11:

What is the conclusion?

Question 12:

The analyst then conducted an appropriate -test at a significance level of 5% to test the

suspicion. Set up the alternative hypotheses for the -test.

Question 13:

Find the test statistic in the -test.

Question 14:

Find the rejection region in the -test.

Question 15:

What is the conclusion?