Is there any difference between the proportion of americans who wish they were rich and the proportion of Canadians who wish they were rich ? A random sample of Americans showed that 550 wish they were rich, while a random sample of 500 Canadians showed that 225 wished they were rich.
a) find a 97.5% confidence interval for the difference between the population proportions who wish they were rich.
b) Test at the 1% level of significance, whether the two population proportions are significantly different. Formulate and test the appropriate hypotheses. Use the critical value approach.