Question

A 2012 Gallup poll surveyed Americans about their employment status and whether or not they have diabetes. The survey results indicate that 1.5% of the 47,774 employed (full or part time) and 2.5% of the 5,855 unemployed 18-29 year old's have diabetes.
A)Create a two-way table presenting the results of this study.
B)State appropriate hypotheses to test for independence of incidence of diabetes and employment status. Complete the hypothesis test and state an appropriate conclusion.
C)Calculate a 99% confidence interval for the proportion of a difference in the rate of diabetes between employed and unemployed 18-29 year olds., and interpret the interval in this context.

Answer 1

A) See picture for the table.

To make the table, multiply 47774 by 1.5% to get total that have diabetes and multiply 5855 by 2.5% to get total unemployed that have it, then using subtraction fill in the other squares of the table.

B)

Hypothesis:

H0: No association between employment and diabetes.

H1: Association between the two

Using a graphing calculator or Excel, run a chi-test.

Chi squared equals 31.844 with 1 degrees of freedom.

 The two-tailed P value is less than 0.0001

With this information we can reject the null hypothesis and conclude there is an association between diabetes and employment.

C)

Although there is a statistical significance, there really is no practical significance between an incidence rate of 1.5 or 2.5%