a) Suppose now that we also have data on the number of claims by male retirees. The data are now:
Male policyholders: Single Married Retirees
No. Making claims       76           90           45
Sample size                   400       900          250
Assume that the three categories are mutually exclusive. Using a 0.05 significance level and a critical value approach, conduct an appropriate test to determine if there is a significant difference in the proportion of claims among the three groups.

b.  If a significant difference is determined among the three groups, conduct an appropriate test to determine where the significant differences lie.