Homework # 8 Name ____________________________________
Chapters 5 & 14
- What is the "general linear equation"? (½ pt)
1a. Interpret the four components of the general linear equation (1pt)
- What information is conveyed by the slope of a line? (1 pt)
- What information is conveyed by the intercept of a line? (1 pt)
- What information is conveyed by the magnitude of a correlation coefficient? (½ pt)
- What information is conveyed by the sign of a correlation coefficient? (½ pt)
- Why must we be cautious when drawing inferences about causal relationships from correlational analyses? (1 pt)
- What is the coefficient of determination? What information does it provide? (½ pt)
- What information is conveyed by the estimated standard error of estimate? (¾ pt)
8a. What statistical notation is used to represent the estimated standard error of
estimate? (¼ pt)
- Use the following data to compute the correlation coefficient and the regression equation.
|
Individual |
X |
Y |
X2 |
Y2 |
XY |
|
1 |
4 |
5 |
|
|
|
|
2 |
8 |
2 |
|
|
|
|
3 |
3 |
4 |
|
|
|
|
4 |
9 |
10 |
|
|
|
|
5 |
2 |
4 |
|
|
|
|
6 |
1 |
2 |
|
|
|
|
7 |
7 |
8 |
|
|
|
|
8 |
4 |
8 |
|
|
|
|
9 |
1 |
5 |
|
|
|
|
10 |
7 |
9 |
|
|
|
- complete the above table (¾ pt)
- compute the Pearson correlation coefficient (1 ¼ pts)
- test for a relationship between X and Y (½ pt)
- compute and interpret the value of r2 (½ pt)
- what is the nature of the relationship (¼ pt)
- compute the regression equation for predicting Y from X (1 ¼ pts)
- How much error will result when we use the above equation to make
predictions? (½ pt)
- What is the predicted Y score for an X score of 3? What is the predicted Y score for an X score of 8.5? (1 pt)
