4. Suppose that 203 of the 749 observations in group 1 have a characterisitic of interest. And, suppose that 240 of the 744 observations in group 2 have this characterisitic. We want to estimate the end points of a 95% confidence interval for Pi-P2 (a) What is the difference in the sample proportions between groups 1 and 2? (round to 5 digits after the decimal place) 1 (b) What is the standard error for the difference in the sample proportions? (Use the confi- dence interval standard error and round to 5 digits after the decimal place.) (c) What is the estimate of the left end of a 95% confidence interval? (Round to 3 digits after the decimal place.) (d) What is the estimate of the right end of a 95% confidence interval? (Round to 3 digits after the decimal place.) (e) Do we reject or not reject the null hypothesis that the population proportions are the same at the .05 level of significance? Reject Not reject