307 Eco J. Brooks Due: September 17th Using the following data: CLL-data.sav
Homework #1
Taggert
Go to my homepage and download the file called CLL-data.sav. You can also download the file called CLL-prog.sps to help in interpreting the variable names. Or see the appendix to the assignment. For the questions 1- look at the following variables: classif, college, gender, termgpa, cumgpa, actmth, age, perrnk, aptpre, aptpost, final, score, finalgra, control Classify each variable in the data set as either: nominal, ordinal, interval or ratio. Classif nominal (ordinal?) College nominal Gender nominal Termgpa interval (ordinal?) Cumgpa interval (ordinal) Actmth interval Age ratio Perrnk ratio (interval?) Aptpre, aptpost, final, score ratio Finalgra ordinal (interval?) Control nominal
2. Describe each variable using both an appropriate statistic and graphical representation. Note: it may be useful to recode some variables, like finalgra for example. There are many possible correct answers here. Some examples of descriptive statistics are found below, see the SPSS output file for examples of appropriate graphs:
classif Frequency 84 23 38 18 12 3 4 4 1 187 Percent 44.9 12.3 20.3 9.6 6.4 1.6 2.1 2.1 .5 100.0 Valid Percent 44.9 12.3 20.3 9.6 6.4 1.6 2.1 2.1 .5 100.0 Cumulative Percent 44.9 57.2 77.5 87.2 93.6 95.2 97.3 99.5 100.0
Valid
1 2 3 4 5 6 8 9 J Total
college Frequency 113 9 20 22 23 187 Percent 60.4 4.8 10.7 11.8 12.3 100.0 Valid Percent 60.4 4.8 10.7 11.8 12.3 100.0 Cumulative Percent 60.4 65.2 75.9 87.7 100.0
Valid
B E H L P Total
gender Frequency 93 94 187 Percent 49.7 50.3 100.0 Valid Percent 49.7 50.3 100.0 Cumulative Percent 49.7 100.0
Valid
F M Total
finalgra Frequency 7 23 21 49 34 17 20 171 16 187 Percent 3.7 12.3 11.2 26.2 18.2 9.1 10.7 91.4 8.6 100.0 Valid Percent 4.1 13.5 12.3 28.7 19.9 9.9 11.7 100.0 Cumulative Percent 4.1 17.5 29.8 58.5 78.4 88.3 100.0
Valid
Missing Total
1.00 2.00 3.00 4.00 5.00 6.00 7.00 Total System
control Frequency 92 95 187 Percent 49.2 50.8 100.0 Valid Percent 49.2 50.8 100.0 Cumulative Percent 49.2 100.0
Valid
.00 1.00 Total
Looking at the Interval/Ratio scaled variables we have:
Descriptive Statistics N actmth cumgpa age aptpre aptpost final score termgpa Valid N (listwise) 159 186 187 141 170 170 170 184 123 Minimum 14 0 17.76 1 4 12 8 0 Maximum 34 400 37.13 12 20 54 34 400 Mean 22.89 286.50 19.9879 6.30 11.89 34.75 22.85 274.78 Std. Deviation 3.633 64.313 2.36225 2.283 3.450 7.854 5.418 74.069
3. Looking at (describe) college, classif, cumgpa, actmath, and final, by gender and by control. For some you may provide an appropriate graphic description do there look to be differences? There are many possible correct answers here.
4. For the above bivariate relationships do the appropriate statistical test to see if there are differences Note: For the following Chi-squared tests it is important that every cell have a minimum expected count of 5 observations in order for the statistic to be valid, and inference to be appropriate. If you notice in every case below there are at least 2 cells that don't meet this requirement. So you should combine categories where appropriate to over come this problem. Your answers should be different, but they will depend on how you combined categories. college gender
COLLEGE * SEX Crosstabulation Count SEX F COLLEGE B E H L P 54 7 10 9 13 93 M 59 2 10 13 10 94 Total 113 9 20 22 23 187
Total
Chi-Square Tests Value 4.112a 4.282 187 df 4 4 Asymp. Sig. (2-sided) .391 .369
Pearson Chi-Square Likelihood Ratio N of Valid Cases
a. 2 cells (20.0%) have expected count less than 5. The minimum expected count is control
COLLEGE 4.48.
college * CONTROL Crosstabulation Count CONTROL .00 1.00 52 61 8 1 11 9 9 13 12 11 92 95 Total 113 9 20 22 23 187
COLLEGE
B E H L P
Total
Chi-Square Tests Value 7.086a 7.842 187 df 4 4 Asymp. Sig. (2-sided) .131 .098
Pearson Chi-Square Likelihood Ratio N of Valid Cases
a. 2 cells (20.0%) have expected count less than 5. The minimum expected count is 4.43.
classif control
CLASSIF * CONTROL Crosstabulation Count CONTROL .00 1.00 43 41 22 1 17 21 4 14 4 8 1 2 1 3 4 1 92 95 Total 84 23 38 18 12 3 4 4 1 187
CLASSIF
1 2 3 4 5 6 8 9 J
Total
Chi-Square Tests Value 32.825a 39.640 187 df 8 8 Asymp. Sig. (2-sided) .000 .000
Pearson Chi-Square Likelihood Ratio N of Valid Cases
a. 8 cells (44.4%) have expected count less than 5. The minimum expected count is .49.
classif gender
CLASSIF * SEX Crosstabulation Count SEX F CLASSIF 1 2 3 4 5 6 8 9 J 42 7 23 9 7 2 2 1 93 M 42 16 15 9 5 1 2 3 1 94 Total 84 23 38 18 12 3 4 4 1 187
Total
Chi-Square Tests Value 7.867a 8.417 187 df 8 8 Asymp. Sig. (2-sided) .447 .394
Pearson Chi-Square Likelihood Ratio N of Valid Cases
a. 8 cells (44.4%) have expected count less than 5. The minimum expected count is .50.
The follwing three t-tests for mean difference with independent samples can be found below. cumgpa gender (this appears to be the only significant difference in means...females have a higher GPA) actmth gender (no sig diff) final gender (no sig dif)
Independent Samples Test Levene's Test for Equality of Variances t-test for Equality of Means Mean Difference 31.60 31.60 -.82 -.82 1.37 1.37 Std. Error Difference 9.165 9.165 .576 .582 1.204 1.202
F CUMGPA Equal variances assumed Equal variances not assumed Equal variances assumed Equal variances not assumed Equal variances assumed Equal variances not assumed 1.616
Sig. .205
t 3.448 3.448
df 184 171.713 157 144.029 168 166.105
Sig. (2-tailed) .001 .001 .157 .162 .256 .256
ACTMTH
1.714
.192
-1.421 -1.405
FINAL
1.473
.227
1.139 1.140
The following three t-tests for mean difference with independent samples can be found below. cumgpa control (at the 5% level no sig dif, there is at the 10% level) actmth control (at the 5% level no sig dif...