Suppose we surveyed 1016 Canadian adults (assume half men and half women) and found that 65% of men and 45% of women support scrapping the five-cent coin (the nickel).

a) Construct a 90% confidence interval for the difference in support for scrapping the nickel between men and women.

b) Construct a 99% confidence interval for the difference in support for scrapping the nickel between men and women.

c) Interpret the meaning of the fact that one of these confidence intervals is wider than the other.

d) If we wanted the 90% confidence interval in (a) to be one-quarter as wide (narrower by 75%), how many more people would we need to survey? Answer the same question for the 99% confidence interval in (b).