(6.3).5

A researcher wishes to estimate, with

90%

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

4%

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

20%

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

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

Question content area bottom

Part 1

(a) What is the minimum sample size needed assuming that no prior information is available?

n=enter your response here

(Round up to the nearest whole number as needed.)