To: sbaker@odu.edu
From: Thomas Meyer
tmeyer@ph.vccs.edu
276 656-0283
Patrick Henry Community College
Subject: Statistics - w/ Dr.Spencer Baker - Homework Assignment #3, Ch 7 - Problem 15, page198.
Date: March 20, 2004
Here's the general algorithm for doing this problem:
1. Get the data
2. Manipulate the data
To do a scatterplot:
Select Graph
Scatterplot
Define (followed by reset if necessary)
Move the independent variable (also called the predictor variable) to the
x-axis
Move the dependent variable (also called the criterion variable) to the y-axis
Click OK
To plot a linear regression between the independent and
dependent variable on the scatterplot:
(See text page 188-189 for instructions.)
Double-click the scatterplot to invoke the Graph Editor
From Chart Menu, select Options...
Click Fit Line Total box
Click OK
To find the
linear regression equation between the independent and dependent variable:
From the SPSS Editor
Open Analyze menu
Select Regression ... linear
Enter the independent variable and the dependent variable
Click OK
3. Do something with the data
Right-click the scatterplot and regression diagram box
Select copy object
Paste the copied object into FrontPage (Before you paste the object,
right-click and read the"results coach")
Save your work
Send it on to the instructor
Question:
Use the SPSS program and SPSS data bank to find the regression analysis and
equation for each of the following.
a. The predictor variable (independent variable) post-instruction math attitude (postatt) and the criterion variable (dependent variable) final algebra grade point average (algpa) from the data file math.sav.
Answer:
From the previous table, the results coach says that "the unstandaridized coefficients are the coefficients of the estimated regression model."
The general equation for a straight line may be thought of as Y = mX + b with
m = slope and b = the intercept on the Y-axis when X = 0.
So we move the decimal two places to the left in -3.37E-02 to find the slope;
and we also use 4.367 as the intercept on the Y-axis.
| Therefore, Final algebra grade = -.0377 X (Post-instruction math attitude) + 4.367 |
Question:
b. The predictor variable (independent variable)
post-instruction math attitude (postatt) and the criterion variable (dependent
variable) mathematics score on the Iowa Test of Educational Development for 9th
Graders (ited9) from the data file math.sav.
Answer:
From the previous table, the results coach says that "the unstandaridized coefficients are the coefficients of the estimated regression model."
The general equation for a straight line may be thought of as Y = mX + b with
m = slope and b = the intercept on the Y-axis when X = 0.
So we use -.526 to find the slope; and we
also use 100.971 as the intercept on the Y-axis.
| Therefore, ITED 9th Grade Math Score = -.526 X (Post-instruction math attitude) + 100.971 |
Question:
c. The predictor variable (independent variable) confidence in doing mathematics (confmath) and the criterion variable (dependent variable) final grade in mathematics (fingrd) from the data file career.sav.
Answer:
From the previous table, the results coach says that "the unstandaridized coefficients are the coefficients of the estimated regression model."
The general equation for a straight line may be thought of as Y = mX + b with
m = slope and b = the intercept on the Y-axis when X = 0.
So we move the decimal two places to the left in 6.790E-02
to find the slope; and we also use -.551 as the
intercept.
| Therefore, Final grade in math = .06790 X (Confidence in doing math) - .551 |
Question:
d. The predictor variable (independent variable) empathic concern (empathy) and the criterion variable (dependent variable) altruism (altruism) from the data file donate. sav.
Answer:
From the previous table, the results coach says that "the unstandaridized coefficients are the coefficients of the estimated regression model."
The general equation for a straight line may be thought of as Y = mX + b with
m = slope and b = the intercept on the Y-axis when X = 0.
So we use .616 to find the slope; and we also use
15.354 as the intercept on the Y-axis.
| Therefore, Altruism = .616 X (Empathic Concern) + 15.354 |
filename: StatHW3Ch7Prob15page198TomMeyer.doc
Tom Meyer
Thomas Meyer