1. Are delinquent teens more likely to be older than teens who don't report delinquency? One way to look at this question is with a ttest. In this case, we'll compare the mean age for delinquent students with the mean age of non-delinquent students: a. State research and null hypotheses for this topic. b. What type of test should you use: an independent-samples ttest or a matched-group test? c. For this analysis, use an alpha of .001 for your signicance level. (1 . Conducting an independent-samples ttest in SPSS: To run a ttest in SPSS, select analyze->compare means-> independent-samples t-test. Put the variable \"V2" (age) in the \"test variable\" box. Click \"define groups\" and enter 0 in one box and 1 in the other. Then, put our grouping variable, \"D1,\" in the \"grouping variable\" box. Select 0k: 1. The output for this needs some explanation. The rst box that comes out tells you the number of cases in each group (n) and the mean and standard deviation for each group. The second box has two rows that cor- respond to ttests conducted with equal or unequal variances assumed. Levene's test for equality of vari- ances is an F test comparing group variances that will be addressed in a later question. You are interested in the columns labeled \"T\" and \"sig. 2-tailed\"; these are your test statistic and its exact p value. Also of interest is the \"mean difference\" box, which contains the value for the mean of group 1 minus the mean of group 2. e. Assume that a difference of .15 in standard deviation is evidence that you have unequal variances. After looking at the standard deviations for either group, do you conclude that these groups have equal or unequal variances? f. By using the appropriate variance assumptions, what do you conclude about the null hypothesis? g. Write a sentence explaining what this result tells us about delinquency in substantive terms. Group Statistics Std. Std. Error deling 1 dichotomized N Mean Deviation Mean age 1 or fewer acts 379 15.08 487 025 2 or more acts 893 15.14 .515 017 Independent Samples Test Levene's Test for Equality of Variances t-test for Equality of Means 95% Confidence Interval of Significance Mean Std. Error the Difference F Sig. df One-Sided p Two-Sided p Difference Difference Lower Upper age Equal variances 4.588 .032 -2.029 1270 .021 .043 -.063 031 -.124 -.002 assumed Equal variances not -2.076 750.964 019 038 -.063 .030 -.123 -.003 assumed