1. The 95% confidence interval required is for the difference in the proportion of single male and single female credit card holders who have Gold cards.

a. Calculate the 95% C.I., show your working and express the CI in the standard notation.

b. Interpret your CI in context.

c. Show the necessary conditions hold for the CI to be valid.

2. Does our data provide sufficient evidence that the average Income of single male card holders is greater than the average Income of single female cardholders?

a. Write out the appropriate null and alternative hypotheses for this test. b. Can we assume equal variances for this test? c. From the appropriate SPSS output, state the value of the test statistic and use the p-value to make the decision

the test. (Use ? = 0.05) d. Interpret your result in context. e. Show that the necessary condition/s hold for this test to be valid.

Type * Cardholders Crosstabulation Cardholders Single Single Male Female Total Type Gold Count 54 8 62 % within Cardholders 14.6% 2.6% 9.2% Standard Count 282 256 538 % within Cardholders 76.2% 83.7% 79.6% Low Interest Count 34 42 76 % within Cardholders 9.2% 13.7% 11.2% Total Count 370 306 676 % within Cardholders 100.0% 100.0% 100.0%T-Test Group Statistics Std. Error Cardholders N Mean Std. Deviation Mean Income Single Male 370 $43,764.59 $19,444.478 $1,010.870 Single Female 306 $38,213.07 $11,270.514 $644.292 Independent Samples Test Levene's Test for Equality of Variances t-test for Equality of Means 95% Confidence Interval of the Mean Std. Error Difference F Sig. df Sig. (2-tailed) Difference Difference Lower Upper Income Equal variances 75.642 <.001 assumed equal variances not>