Question

A researcher wishes to​ estimate, with

9595​%

​confidence, the population proportion of adults who think Congress is doing a good or excellent job. Her estimate must be accurate within

33​%

of the true proportion.

​(a) No preliminary estimate is available. Find the minimum sample size needed.

​(b) Find the minimum sample size​ needed, using a prior study that found that

4040​%

of the respondents said they think Congress is doing a good or excellent job.

​(c) Compare the results from parts​ (a) and​ (b).

Answer 1

(a)

(b)

(c) sample size is smaller for part(b)