Illinois State University Mathematics Department

 MAT 312: Probability and Statistics for Middle School Teachers Dr. Roger Day (day@ilstu.edu)

### Assignment #3

possible solutions

Assignment due on Thursday, 6/24/04

Use the Couples' Ages data set, handed out in class, to complete the following tasks.

1. Create the equation for the median-median line of this data set, using husband's ages as the first element (x) of each ordered pair and wife's ages as the second element (y) in each ordered pair. Show all steps in the process as we illustrated in class and express your equation in slope-intercept form. You can check the equation of your median-median line using your calculator.

2. Use your calculator to generate the least-squares linear regression equation for this data set, using husband's ages as the first element (x) of each ordered pair and wife's ages as the second element (y) in each ordered pair. Copy all the information your calculator shows you when you generate the least-squares equation. Express your equation in slope-intercept form.

3. Calculate the sum of the squared error terms (SSE) for each of the models you just created (i.e., for the median-median line and for the least-squares line). You are encouraged to use your calculator's "lists" features to carry out your calculations. Express each sum rounded to the nearest hundredth of a unit.

Complete this assignment using pencil and paper and bring it to class for discussion and submission. You may use a calculator for any parts of the assignment and copy the calculator information onto your paper.