An analyst at a local bank wonders if the age distribution of customers coming for service at his branch in town is the same at a branch located near the mall. He selects 100 transactions at random from each branch and researches the age information for the associated customer. These are the data:

Age

Less than 30 30-55 56 or older Total

In town 25 37 38 100

mall 30 48 22 100

Total 55 85 60 200

OUESTIONS:

1. What is the null hypothesis if you want to check if the age patterns of customers are independent of bank location?

2. What are the expected numbers for each cell in a 3 by 3 table if the null hypothesis is true?

Age

Less than 30 30-55 56 or older Total

In town

mall

Total

3. Use the chi square test to accept or reject the null hypothesis. What is the chi square test statistic?

4. What is the chi square critical value and how many degrees of freedom does it have? Assume alpha is .05.

5. What do you conclude?