(a)[1]
Nikki’s friend says that, since this survey is about sports facilities, a sample of students should be chosen from the school sports teams. State, giving a reason, whether you agree with Nikki’s friend.
(b)[3]
Nikki selects an appropriate random sample of 60 students. She discovers that 45 of these students think that the sports facilities are good. Calculate an approximate 95% confidence interval for the proportion of students who think that the sports facilities are good.
(c)[4]
For a different investigation, Nikki uses another large random sample to find a 99% confidence interval and an $x\%$ confidence interval. The width of the 99% confidence interval is twice the width of the $x\%$ confidence interval. Calculate the value of $x$.