Question

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

	Less than 30	30 - 35	56 and older	Total
In-Town Branch	20	40	40	100
Mall Branch	30	50	20	100
Total	50	90	60	200

Show your work for the questions that require calculations.

1. What is the null hyposthesis?
2. What type of test is this?
3. What are the expected numbers for each cell if the null hypothesis is true?
4. Find the X² statistic.
5. How many degrees of freedom does it have?
6. Find the P-value.
7. What do you conclude?

Answer 1

(a) H0 : the age distribution of customers coming for service at his branch in town is the same as at the branch located near the mall.

(b) Chi square test

(c)

(d)

(e)

(f)

(g) Since the P-value is very small, we reject H0.

That is, the age distribution of customers coming for service at his branch in town is NOT same as at the branch located near the mall.