A local school board would like to test the hypothesis that the proportion of Americans who think unions have a positive effect on schools has increased this year when compared to last year. The table given below shows the data from the survey done this year compared with that done last year. Dene Population 1 as this year and Population 2 as last year and use the critical value approach to test this hypothesis with = 0.05. This Year Last Year Number in sample 155 150 Number of Americans who think unions have a positive effect on schools 60 52 a) (1 marks) Calculate the sample proportions for each group (Last year and this year), and the point estimate of the difference between groups. b) (3 marks) Calculate a 99% condence interval for the difference between population proportions. c) (6 marks) Test the hypothesis that the population proportion for this year is greater than that for last year, at the 95% confidence level. For this question, perform your calculation using the formulas do not use the Analysis Toolpak tools. Show all parts of the hypothesis test, including your hypothesis, your test-statistic calculations, P value calculations and your conclusion