Assignment:
Q1. What proportion of Americans get most of their news from the internet? According to a poll conducted by Pew Research Center, 40% get most of their news from the Internet.
a. To conduct a follow-up study that would provide 95% confidence that the point estimate is correct to within +/- 0.04 of the population proportion, how large a sample size is required?
b. To conduct a follow-up study that would provide 99% confidence that the point estimate is correct to within +/- 0.04 of the population proportion, how many people need to be sampled?
c.To conduct a follow-up study that would provide 95% confidence that the point estimate is correct to within +/- 0.02 of the population proportion, how large a sample size is required?
d. To conduct a follow-up study that would provide 99% confidence that the point estimate is correct to within +/- 0.02 of the population proportion, how many people need to be sampled?
e. Discuss the effects of sample size requirements of changing the desired confidence level and the acceptable sampling error.
Q2. A stationary store wants to estimate the total retail values of the 1000 greeting cards it has in its inventory. Construct a 95% confidence interval estimate for the population total value of all greeting cards that are in inventory if a random sample of 100 greeting cards indicates a mean value of $2.55 and a standard deviation of $0.44.
Q3. An internal control policy for Rhonda's Online Fashion Accessories requires a quality assurance check before a shipment is made. The tolerable exception rate for this internal control is 0.05. During an audit, 500 shipping records were sampled from a population of 5000 shipping records, and 12 were found that violated the internal control.
| Number |
Company |
Compensation |
| 10 |
Aflac |
10,783,232 |
| 60 |
Big lots |
9,862,262 |
| 110 |
Comerica |
4,108,245 |
| 160 |
EMC |
13,874,262 |
| 210 |
Harley Davidson |
6,048,027 |
| 260 |
Kohl's |
11,638 ,049 |
| 310 |
Molson Coors Brewing |
5,558,499 |
| 360 |
Pfizer |
6,629,955 |
| 410 |
Sigma-Aldrich |
3,983,596 |
| 460 |
United Parcel Service |
5,168,664 |
a. Calculate the upper bound for a 95% one-sided confidence interval estimate for the rate of noncompliance.
b. Based on (a), what should the auditor conclude?