Many college graduates who are employed full-time have longer than 40-hour work weeks. Suppose that we wish to estimate the mean number of hours, μ, worked per week by college graduates employed full-time. We'll choose a random sample of college graduates employed full-time and use the mean of this sample to estimate μ. Assumi
Please see the attached file. A company wants to conduct a telephone survey of randomly selected voters to estimate the proportion of voters who favor a particular candidate in a presidential election, to within 2% error with 95% confidence. It is guessed that the proportion is 53%. 1. What is the required minimum sampl
1) In order to set rates, an insurance company is trying to estimate the number of sick days that full time workers at an auto repair shop take each year. A previous study indicated the standard deviation was 2.8 days. How large a sample must be selected if the company wants to be 95% confident that the true mean differs from th
Please show me how you solved problem below: A member of Congress wants to determine her popularity in a certain part of the state. She indicates that the proportion of voters who will vote for her must be estimated within plus or minus 2 percent of the population proportion. Further, the 0.95 degree of confidence is to be
A processor of carrots cuts the green top off each carrot, washes the carrots, and inserts six to a package. Twenty packages are inserted in a box for shipment. To test the weight of the boxes, a few were checked. The mean weight was 20.4 pounds, the standard deviation 0.5 pounds. How many boxes must the processor sample to be 9
A researcher has reason to be that, for an experiment with 50 points, a 95% prediction interval would be of width 4. If the researcher wishes to run a more precise experiment that will result in a 95% prediction interval of width 2, then the researcher will require A) 200 points B) More than 200 points C) 50 points
A union of restaurant and food service workers would like to estimate the mean hourly wage, , of food service workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be 90% confident that its estimate is w
A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to estimate the mean monthly mileage, , of cars rented in the U.S. over the past year. The consumer group plans to choose a random sample of monthly U.S. rental car mileages and then estimate using the mea
A previous analysis of paper boxes showed that the standard deviation of their lengths is 13 millimeters. A packer wishes to find the 80% confidence interval for the average length of a box. How many boxes does he need to measure to be accurate within 3 millimeters? a.14 b.19 c.51 d.31
A previous study of nickels showed that the standard deviation of the weight of nickels is 250 miligrams. A coin counter manufacturer wishes to find the 90% confidence interval for the average weight of a nickel. How many nickels does he need to weigh to be accurate within 15 miligrams? a. 457 b. 278 c. 752 d. 1068
A researcher conducted a study of the access speed of 45 hard drives and concluded that the maximum error of estimate was .28. If he were to conduct a second study to reduce the maximum error of estimate to 7, about how many hard drives should he include in his sample? a. 720 b. 180 c. 45 d. 90
Suppose that, in a school with 1,348 students, 137 students are left-handed. You survey 100 students and find that 11 of the students in your sample are left handed. What is the population proportion of left handed students? What is the sample proportion of left-handed students? Does your sample appear to be representative
You wish to estimate, with 95% confidence, the proportion of camcorders that need repairs or have problems by the time the product is 5 years old. Your estimate must be accurate within 5% of the true proportion. a. Find the minimum sample size needed, using a prior study that found that 25% of the camcorders needed repairs
True or False with justification Of these two formulas, 7-2 and 7-3, the first one never results in a greater sample size than the second formula. Formula 7-2 n = When an estimate is known. Formula 7-3 n = When no estimate is known. See attached.
You wish to estimate accurately with 95% confidence and within 3% of the true population, the proportions of television sets that need repairs or have problems by the time the product is three years old. If no preliminary estimate is available, what is the minimum sample size required? Please show your work so I can figure out
Determine the sample size needed to estimate (lower case mu / mean of a random variable) for the given situation. E = 4, standard deviation = 35, level of confidence = .90 a. 208 b. 295 c. 4 d. 207
A study of elephants wishes to determine the average weight of a certain type of elephant. The standard deviation of the population is 500 pounds. How many elephants need to be weighed so find we can be 95% confident to be accurate within 300 pounds?
The amount of coffee that a filling machine puts into an 8-ounce jar is normally distributed with a mean of 8.2 ounces and a standard deviation of 0.18 ounce. Determine the percentage of samples of size 16 that will have mean amounts of coffee within 0.1 ounce of the population mean of 8.2 ounces. Put your answer to two place
In computing sample size for estimating population proportions, the formula involves p(1-p) (where we don't know p). We use p = ½ if we don't know anything about it, since that is a "worst case". Find the values of p(1-p) for p=.01, .02, .05, .10, .15, .20, .30, .40., .50, .60, .70,.80, .85, .90, .95, .98, and.99. Be prepared t
Why is it important to determine the size of a sample precisely? What are the key points to consider when determining sample size? Frame your answer with business-related examples in mind.
Chapter 6 (Book "Sampling of Populatations" 3rd edition) 1. Ester is an epidemiologist and body builder She is planning a survey of Chicago area body builders to determine the proportion who have ever used anabolic steroids. Her sampling frame consists of membership lists obtained from all accredited health clubs in the six
Select one of these articles and provide an overview of the contents and apply the concepts to the Job Satisfaction survey. It is important to cover the concept of the techniques used to estimate sample size. Simple rules shape proper sample size Section: Special report RESEARCH ? A numbers game How low can you go? No,
Question: The estimate of the population proportion is to be within plus or minus .10, with a 99 percent level of confidence. The best estimate of the population proportion is .45. How large a sample is required?
A sample of n = 300 items has been randomly selected. Of these, 55 contain the attribute of interest. Based on this information, compute a 90% confidence interval estimate for the proportion of items in the population that have this attribute. Assume that a decision maker wants to estimate a population proportion with 90% con
The CEO of a company wants to estimate the proportion of Americans who own their house. What sample size should be obtained if he wants the estimate to be within 0.02 with 90% confidence if a. He uses an estimate of 0.675 from the American Census Bureau? b. He does not use any prior estimates?
A processor of carrots cuts the green top off each carrot, washes the carrots, and inserts six into a package. Twenty packages are inserted in a box for shipment. To test the weight of the boxes, a few were checked. The mean weight was 20.4 pounds, with a standard deviation of 0.5 pounds. How many boxes must the processor sample
Business Problem Paper and Optional Presentation a. Clearly define the dependent and independent variables that are the focus of the team's study. The dependent variable is the variable whose value is the result or is a function of the control or independent variables. b. State the null and alternative hypotheses and the
A certain confidence in interval is 7.05 < U <8.35. Find the sample mean and error of estimate. Show the formula.
a. Using the .90 degree of confidence, management wants to estimate the percentage of the tourists spending more than $1,000 within 1 percent. What sample size should be employed? b. Management said that the sample size suggested in part a is muc
A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to estimate the mean monthly mileage, , of cars rented in the U.S. over the past year. The consumer group plans to choose a random sample of monthly U.S. rental car mileages and then estimate using the mea