EXERCISES I -

Answers to selected exercises are downloadable at www.pearsonhighered.com/george

For questions 1 - 7, perform the following operations:

a) Print out results

b) Circle the two mean values that are being compared.

c) Circle the appropriate significance value (be sure to consider equal or unequal variance)

d) For statistically significant results (p < .05) write up each findings in standard APA format.    

1. Using the grades.sav file, compare men with women (gender) for quiz1, quiz2, quiz3, quiz4, quiz5, final, total. 

2. Using the grades.sav fie, determine whether the following pairings produce significant differences: quiz1 with quiz2, quiz1 with quiz3, quiz1 with quiz4, quiz1 with quiz5.

3. Using the grades.sav file, compare the GPA variable (gpa) with the mean GPA of the university of 2.89.

4. Using the divorce.sav file, compare men with women (sex) for lsatisfy, trauma, age, school, cogcope, behcope, avoicop, iq, close, locus, asq, socsupp, spiritua.

5. Using the heiping3.sav file, compare men with women (gender) for age, school, income hclose, hcontrot, sympathy, angert, hcopet, hseveret, empathy, effict, thelplnz, tqualitz, tothelp. See the Data Files section (page 365) for meaning of each variable.

6. Using the helping3.sav fie, determine whether the following pairings produce significant differences: sympathy with angert, sympathy with empathy, empahelp with insthelp empahelp with infhelp, insthelp with infhelp.

7. Using the helping3.sav file, compare the age variable (age) with the mean age for North Americans (33.0).

8. In an experiment, 10 participants were given a test of mental performance in stressful situations. Their scores were 2, 2, 4, 1, 4, 3, 0, 2, 7, and 5. Ten other participants were given the same test after they had been trained in stress-reducing techniques. Their scores were 4, 4, 6, 0, 6, 5, 2, 3, 6, and 4.  Do the appropriate t test to determine if the group that had been trained had different mental performance scores than the group that had not been trained in stress reduction techniques. What do these results mean?

9. In a similar experiment, ten participants who were given a test of mental performance in stressful situations at the start of the study, were then trained in stress reduction techniques, and were finally given the same test again at the end of the study. In an amazing coincidence, the participants received the same scores as the participants in question 8. The first two people in the study received a score of 2 on the pretest, and a score of 4 on the posttest; the third person received a score of 4 on the pretest and 6 on the posttest and so on. Do the appropriate t test to determine if there was a significant difference between the pretest and posttest scores. What do these results mean? How was this similar and how was this different than the results in question 1? Why?        

10. You happen to know that the population mean for the test o mental performance in stressful situations is exactly three. Do a t test to determine whether the post-test scores in #9 above (the same numbers as the training group scores in #8) is significantly different than three. What do these results mean? How was this similar and how was this different than the results in question 2? Why?

EXERCISES II -

Answers to selected exercises are downloadable at www.pearsonhighered.com/george.

Perform one-way ANOVAs with the specifications listed below. If there are significant findings write them up in APA format (or in the professional format associated with your discipline). Examples of correct APA format are shown on the web site. Further, notice that the final five problems make use of the helping3.sav data file. This data set (and all data files used in the book) is also available for download at the website listed above. For meaning and specification of each variable, make use of Data Files section of this book beginning on page 385.

1. File: grades.sav; dependent variable: quizi4; factor: ethnic (2, 5); use LSD Procedure for post hoc comparisons, compute two planned comparisons. This problem asks you to reproduce the output on pages 150-152. Note that you will need to perform a select-case procedure (see page 146) to delete the "1 to Native" category.

2. File: helping3.sav; dependent variable: tothelp; factor: ethnic (1, 4); use LSD procedure for post hoc comparisons, compute two planned comparisons.

3. File: helping3.sav; dependent variable: tothelp; factor: problem (1, 4); use LSD procedure for post hoc comparisons, compute two Planned comparisons.

4. File: helping3.sav; dependent variable: angert; factor: occupant (1, 6); use LSD procedure for post hoc comparisons, compute two planned comparisons.

5. File: helping3.sav; dependent variable: sympathi; factor occupat (1, 6); use LSD procedure for post hoc comparisons, compute two Planned comparisons.

6. File: helping3.sav: dependent variable: effect; factor: ethnic (1, 4); use LSD procedure for post hoc comparisons, compute two Planned comparisons.