Question

1.)

The estimate of the population proportion is to be within plus or minus 0.02, with a 90% level of confidence. The best estimate of the population proportion is 0.18. How large a sample is required? (Use z Distribution Table.) (Round the z-values to 2 decimal places. Round up your answer to the next whole number.)

2.)

In a poll to estimate presidential popularity, each person in a random sample of 1,390 voters was asked to agree with one of the following statements:

1.	The president is doing a good job.
2.	The president is doing a poor job.
3.	I have no opinion.

A total of 675 respondents selected the first statement, indicating they thought the president was doing a good job.

a.	Construct a 99% confidence interval for the proportion of respondents who feel the president is doing a good job. (Use Student's t Distribution Table.) (Round your answers to 3 decimal places.)

3.)

The proportion of public accountants who have changed companies within the last three years is to be estimated within 5%. The 95% level of confidence is to be used. A study conducted several years ago revealed that the percent of public accountants changing companies within three years was 19. (Use z Distribution Table.) (Round the z-values to 2 decimal places. Round up your answers to the next whole number.)

a.	To update this study, the files of how many public accountants should be studied?

b.	How many public accountants should be contacted if no previous estimates of the population proportion are available?

Answer 1