Kusno, a trainee podiatrist, wants to understand how many adults have toenail fungus. Kusno stops students as they enter Gate 2 at UNSW Sydney and shows them photos of typical toenail fungi. Of the students asked, 66 said they had no toenail fungus and 23 said they had at least one toenail fungus. Kusnoasks you to compute the appropriate 90% confidence interval for these data.

(a) Is this an observational study or a designed experiment? Explain your answer briefly.

(b)The appropriate confidence interval you will calculate estimates which population parameter?

p (one group, binary outcome)

(one group, quantitative outcome)

12(two independent groups, quantitative outcome)

D(paired groups, quantitative outcome)

1(two quantitative variables)

(c) What is the appropriate 90% confidence interval for these data?

(d) Interpret this 90% confidence interval in plain English, and specifically referring to the scenario given.