Part -1:
EXERCISES
Answers to selected exercises
1. Using the grades.sav file create a correlation matrix of the following variables; id, ethnic, gender, year section, gpa, quiz1, quiz2, quiz3, quiz4, quiz5, final, total; selected one-tailed significance; flag significant correlations. Print out results on a single page.
• Draw a single line through the columns and rows where the correlations are meaningless.
• Draw a double line through cells where correlations exhibit linear dependency.
Circle the 1 "largest" (greatest absolute value) NEGATIVE correlation (the p value will be less than .05) and explain what it means.
• Box the 3 largest POSITIVE correlations (each p value will be less than .05) and explain what they mean.
• Create a scatter plot of gpa by total and include the regression line. (see Chapter 5,
page 97-98 for instructions).
2. Using the divorce.sav file create a correlation matrix of the following variables; sex, age, sep, mar, status, ethnic, school, income, avoicop, iq, close, locus, asq, socsupp, tua, trauma, Isatisy; select one-tailed significance; flag significant correlations. Print results on a single page. Note: Use Data Files descriptions (p. 385) for meaning of variables.
Draw a single line through the columns and rows where the correlations are meaning-less.
Draw a double line through the correlations where there is linear dependency
Circle the 3 "largest" (greatest absolute value) NEGATIVE correlations (each p value will be less than .05) and explain what they mean.
Box the 3 largest POSITIVE correlations (each plain what they mean p value will be less than .05) and ex-5, page 97-98 for instructions).
Create a scatter plot of close by Isatisy and include the regression line.
Create a scatterplot of avoicop by trauma and include the regression line.
Part -2:
WITHIN-GROUP SUM OF SQUARES - The sum of the squared deviations between the mean for each group and the observed values of each subject within that group.
BETWEEN-GROUP SUM OF SQUARES - The sum of squared deviations between the grand mean and each group mean, weighted (multiplied) by the number of subjects in each group.
BETWEEN-GROUPS DEGREES OF FREEDOM - Number of groups minus one: (3 - 1 = 2)
WITHIN-GROUPS DEGREES OF FREEDOM - Number of subjects minus number of groups (105 - 3 = 102)
MEAN SQUARE - Sum of squares divided by degrees of freedom.
F RATIO - Between-groups mean square divided by within-groups mean square.
SIGNIFICANCE - The probability of the observed values happening by chance. The p value indicated here (p = .10) indicates that a marginally significant difference between means may exist among at least one of the three pairings of the three sections.
ETA A measure of correlation between two variables when one of the variables is discrete.
ETA SQUARED - The proportion of the variance in the dependent variable accounted for by the independent variable. For instance, an eta squared of .044 indicates that 4.4% of the variance in the total scores is due to membership in one of the three sections.
EXERCISES
Answers to selected exercises are downloadable at www.pearsonhighered.com/georqe.
1. Using the grades.sav file use the Means procedure to explore the influence of ethnic and section on total. Print output, fit on one page, in general terms describe what the value in each cell means.
2. Using the grades.sav file use the Means procedure to explore the influence of year and section on final. Print output, fit on one page, in general terms describe what the value in each cell means.
3. Using the divorce.sav file use the Means procedure to explore the influence of gender (sex) and marital status (status) on spiritua (spirituality-high score is spiritual). Print output and, in general terms, describe what the value in each cell means.