Reference no: EM1316724
Finding the 90% confidence interval for the population mean.
Profits: Retail Jobs and productivity! How do retail stores rate? One way to answer this question is to examine annual profits per employee. The following data give annual profits per employee (in units of one thousand dollars per employee) for companies in retail sales. (See reference in Problem 9.) Companies such as Gap, Nordstrom, Circuit City, Dillards, JCPenney, Sears, Wal-Mart, Office Depot, and Toys 'ï' Us are included. Assume σ = 3.8 thousand dollars.
4.4
|
6.5
|
4.2
|
8.9
|
8.7
|
8.1
|
6.1
|
6.0
|
2.6
|
2.9
|
8.1
|
-1.9
|
11.9
|
8.2
|
6.4
|
4.7
|
5.5
|
4.8
|
3.0
|
4.3
|
-6.0
|
1.5
|
2.9
|
4.8
|
-1.7
|
9.4
|
5.5
|
5.8
|
4.7
|
6.2
|
15.0
|
4.1
|
3.7
|
5.1
|
4.2
|
|
(a) Use a calculator or appropriate computer software to verify that, for the preceding data, x = 5.1.
(b) Let us say that the preceding data are representative of the entire sector of retail sales companies, Find an 80% confidence interval for μ, the average annual profit per employee for retail sales.
(c) Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits per employee are less than 3 thousand dollars per employee. Do you think that this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b).
(d) Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b).
(e) Repeat parts (b), (c), and (d) for a 95% confidence interval.
Control limits and x bar chart
: Thirty-two samples of 8 items each were collected from a process. The average sample mean is 12 and the average range is 0.10. The upper and lower control limits, respectively, for an:
|
College students'' seating choices and motivation to achieve
: This activity is a revision of an activity found in Real Data: A Statistics Workbook Based on Empirical Data by Z. C Holcomb (1997). Published by Pyrczak Publishing.
|
Computation of beta value
: Computation of Beta Value and The returns from the past 13 quarters on Mercantile Bank Corporation and the market are listed
|
Calculating the marginal physical product
: What is the marginal physical product of the fifth worker? What is the weekly wage of the fifth worker? What does the price of output need to be in order for the firm to profit from hiring the fifth worker?
|
Preceding data are representative of the entire sector
: Let us speek where the preceding data are representative of the entire sector of retail sales companiesSuppose the annual profits are more than 6.5 thousand $ every employee.
|
Finding z values by using normal distribution
: Suppose the assembly times follow normal distribution. Find out z values for 29 and 34 hours. What percent of garages take between 32 hours and 34 hours to erect?
|
Find the weight of stack of books
: A science workbook is one centimeter thick and weighs 75 grams. How much will a one meter high stack of these workbooks weigh, in kilograms? Give your answer as a decimal to the nearest tenth.
|
Control limits using r chart
: Thirty-two samples of 8 items each were collected from a process. The average sample mean is 12 and the average range is 0.10.
|
Profit-maximizing output level and produce price
: Use the following data for a pure monopoly to calculate the firm's-its profit-maximizing output level and produce price;
|