1. For the data below: a. Compute the Pearson correlation. b. Find the regression equation for predicting...
Question:
1. For the data below:
a. Compute the Pearson correlation.
b. Find the regression equation for predicting Y from X.
c. Calculate the predicted Y for each X value, find each residual (Y - ), square each
residual and add the squared values to obtain SSresidual.
X Y
5 10
3 6
6 7
4 3
2 4
2. Find the regression equation for the following set of data.
X Y
4 1
7 16
3 4
5 7
6 7
3. Suppose that a sample of n = 12 pairs of X and Y scores has SSY = 90 and a Pearson
correlation of r = +0.40.
a. What proportion of the variance for the Y scores is predicted by the regression
equation?
b. Does the regression equation predict a significant portion of the variance? Test
with = .05.
4. A sample of n = 15 pairs of X and Y scores produces a Pearson correlation of r = 0.45 with SSY = 90.
a. If the regression equation was found for these scores, how much of the Y variability
would be predicted by the regression equation (SSregression) and how much would not be
predicted (SSresidual)?
b. Does the regression equation predict a significant portion of the variability for the Y
scores? (Equivalently, is the Pearson correlation significant?)
5. A multiple regression equation has R2 = 0.25 and SSY = 90 for a sample of n = 30 people.
a. Test the significance of the regression equation using = .01.
b. Compute the standard error of estimate for the equation.