Week 13: Homework Assignment 7

1. Fitting a straight line to a set of data yields the following prediction line:

Y=3+5x

1. Interpret the meaning of the y intercept, b0
2. Interpret the meaning of the slope, b1
3. Predict the value of y for x=4

2. If the values of x in problem range from 3 to 24, should you use this model to predict the mean value of y when:
3. x = 3?
4. x = -3?
5. x = 23?
6. x = 25?

Note: Each sub-item above is answerable by yes or no.

3. Fitting a straight line to a set of data yields the following prediction line:

Y = 15 – .09x

1. Interpret the meaning of y intercept, b0
2. Interpret the meaning of slope, b1
3. Predict the value for y when x = 5

4. How do you interpret a coefficient of determination, r² = 0.85?

5. If SSR = 45 and SSE = 5 determine SST and compute the coefficient r² and interpret its meaning.

6. If SSR = 66 and SST = 88 compute the coefficient r² and interpret its meaning.

7. If SSE = 10 and SSR = 50 determine SST and compute the coefficient r² and interpret its meaning

8. If SSR = 120, why is it impossible for SST to = 110?

Tutorial for Homework Assignment 7