All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Hire a Tutor
AI Study Help New

Search
Sign In
Register

study help
mathematics
statistics

Questions and Answers of Statistics

For each situation in Exercise 7.9, find an interval that contains (approximately or exactly) 99.73 percent of all the possible sample means. In which cases must we assume that the population is
Suppose that we will randomly select a sample of 64 measurements from a population having a mean equal to 20 and a standard deviation equal to 4.a. Describe the shape of the sampling distribution of
Find the mean of each sample in Exercise
Find the probability distribution of the population of six sample mean grand prizes.
If you select two envelopes, what is the probability that you will receive a sample mean grand prize of at least 50 thousand dollars?
Compare the probability distribution of the four individual grand prizes with the probability distribution of the six sample mean grand prizes. Would you select one or two envelopes? Why?
Recall that the bank manager wants to show that the new system reduces typical customer waiting times to less than six minutes. One way to do this is to demonstrate that the mean of the population of
Recall that a customer is considered to be very satisfied with his or her XYZ Box video game system if the customer’s composite score on the survey instrument is at least 42. One way to show that
n an article in the Journal of Management, Joseph Martocchio studied and estimated the costs of employee absences. Based on a sample of 176 blue-collar workers, Martocchio estimated that the mean
Write formulas that express the central tendency and variability of the population of all possible sample proportions. Explain what each of these formulas means in your own words.
In each of the following cases, determine whether the sample size n is large enough to say that the sampling distribution of p is a normal distribution. a. p = .4, n = 100 b. p =.1, n =10 c. p
In each of the following cases, find the mean, variance, and standard deviation of the sampling distribution of the sample proportion a. p =.5, n = 250 b. p =.1, n = 100 c. p =.8, n =400 d. p
For each situation in Exercise 7.25, find an interval that contains approximately 95.44 percent of all the possible sample proportions. In Exercise 7.25 In each of the following cases, find the mean,
Suppose that we will randomly select a sample of n 100 elements from a population and that we will compute the sample proportion p ˆ of these elements that fall into a category of interest. If the
On February 8, 2002, the Gallup Organization released the results of a poll concerning American attitudes toward the 19th Winter Olympic Games in Salt Lake City, Utah. The poll results were based on
Quality Progress reports on improvements in customer satisfaction and loyalty made by Bank of America. Akey measure of customer satisfaction is the response (on a scale from 1 to 10) to the question:
In the page margin, we list 15 companies that have historically performed well in the food, drink, and tobacco industries. Consider the random numbers given in the random number table of Table 7.1(a)
Again consider the survey of 350 Bank of America customers discussed in Exercise 7.29, and assume that 48% of Bank of America customers would currently express customer delight. That is, assume p =
Based on your results in Exercise 7.30, would it be reasonable to state that the survey’s “margin of error” is +-3 percentage points? + - 6 percentage points? Explain.
An article in Fortune magazine discussed “outsourcing.” According to the article, outsourcing is “the assignment of critical, but noncore, business functions to outside specialists.” This
Fortune magazine reported the results of a survey on executive training that was conducted by the Association of Executive Search Consultants. The survey showed that 75 percent of 300 polled CEOs
When is it appropriate to use stratified random sampling? What are strata, and how should strata be selected?
Explain how to take a systematic sample of 100 companies from the 1,853 companies that are members of an industry trade association.
Explain why it is important to calculate a confidence interval.
In an article in Marketing Science, Silk and Berndt investigate the output of advertising agencies. They describe ad agency output by finding the shares of dollar billing volume coming from various
In an article in Accounting and Business Research, Carslaw and Kaplan investigate factors that influence “audit delay” for firms in New Zealand. Audit delay, which is defined to be the length of
In an article in the Journal of Marketing, Bayus studied the differences between “early replacement buyers” and “late replacement buyers” in making consumer durable good replacement
Explain how each of the following changes as the number of degrees of freedom describing a t curve increases: a. The standard deviation of the t curve. b. The points tα and tα/2.
Using Table A. 4 (page 608), find t.100, t .025, and t.001 based on 11 degrees of freedom. Also, find these t points based on 6 degrees of freedom.
Suppose that for a sample of n = 11 measurements, we find that x-bar = 72 and s = 5. Assuming normality, compute confidence intervals for the population mean m with the following levels of
The bad debt ratio for a financial institution is defined to be the dollar value of loans defaulted divided by the total dollar value of all loans made. Suppose a random sample of seven Ohio banks is
Air traffic controllers have the crucial task of ensuring that aircraft don’t collide. To do this, they must quickly discern when two planes are about to enter the same air space at the same time.
Whole Foods is an all- natural grocery chain that has 50,000 square foot stores, up from the industry average of 34,000 square feet. Sales per square foot of supermarkets average just under $ 400 per
A production supervisor at a major chemical company wishes to determine whether a new catalyst, catalyst XA-100, increases the mean hourly yield of a chemical process beyond the current mean hourly
The mean and the standard deviation of the sample of 65 customer satisfaction ratings in Table are 42.95 and 2.6424, respectively. Calculate a t-based 95 percent confidence interval for μ, the mean
The mean and the standard deviation of the sample of 100 bank customer waiting times in Table are 5.46 and 2.475, respectively. Calculate a t-based 95 percent confidence interval for μ, the mean of
The mean and the standard deviation of the sample of 40 trash bag breaking strengths in Table 1.9 are 50.575 and 1.6438, respectively.a. Use the Excel output in Figure to calculate a t-based 95
Explain what is meant by the margin of error for a confidence interval. What error are we talking about in the context of an interval for μ?
Explain exactly what we mean when we say that a sample of size n makes us 99 percent confident that x̅ is within E units of μ.
Consider a population having a standard deviation equal to 10. We wish to estimate the mean of this population.a. How large a random sample is needed to construct a 95 percent confidence interval for
Referring to Exercise 8.11a, assume that the population standard deviation equals 33. How large a random sample of public owner-controlled companies is needed to make us? In exercise Suppose that a
Under what conditions is the confidence interval [± zα/2 (σ/√n)] for μ valid?
Referring to Exercise 8.12b (page 299), assume that the population standard deviation equals .66. How large a sample of late replacement buyers is needed to make us? In exercise Suppose that a
Referring to Exercise 8.21 (page 307), regard the sample of five trial runs (which has standard deviation 19.65) as a preliminary sample. Determine the number of trial runs of the chemical process
Referring to Exercise 8.20, regard the sample of 10 sales figures (which has standard deviation 32.866) as a preliminary sample. How large a sample of sales figures is needed to make us 95 percent
Referring to Exercise 8.19, regard the sample of 15 alert times (which has standard deviation 1.026) as a preliminary sample. Determine the sample size needed to make us 95 percent confident that
a. What does a population proportion tell us about the population? b. Explain the difference between p and p̂. c. What is meant when a public opinion poll’s margin of error is 3 percent?
Suppose we are using the sample size formula in the box on page 313 to find the sample size needed to make the margin of error in a confidence interval for p equal to E. In each of the following
In each of the following cases, determine whether the sample size n is large enough to use the large sample formula presented in the box on page 311 to compute a confidence interval for p. a. p̂ =
In each of the following cases, compute 95 percent, 98 percent, and 99 percent confidence intervals for the population proportion p. a. p̂ = .4 and n = 100 b. p̂ = .1 and n = 300 c. p̂ = .9 and
In a news story distributed by the Washington Post, Lew Sichelman reports that a substantial fraction of mortgage loans that go into default within the first year of the mortgage were approved on the
Suppose that 60 percent of 1,000 randomly selected U.S. adults say that they take part in some form of daily activity to keep physically fit. Based on this finding, find a 95 percent confidence
In an article in the Journal of Advertising, Weinberger and Spotts compare the use of humor in television ads in the United States and the United Kingdom. They found that a substantially greater
Consider the marketing ethics case described in Example 8.8. One of the scenarios presented to the 205 marketing researchers is as follows:A marketing testing firm to which X company gives most of
In an article in CA Magazine, Neil Fitzgerald surveyed Scottish business customers concerning their satisfaction with aspects of their banking relationships. Fitzgerald reports that, in 418 telephone
The manufacturer of the ColorSmart-5000 television set claims 95 percent of its sets last at least five years without needing a single repair. In order to test this claim, a consumer group randomly
Consumer Reports (January 2005) indicates that profit margins on extended warranties are much greater than on the purchase of most products. In this exercise we consider a major electronics retailer
Consider Exercise 8.39 and suppose we wish to find the sample size n needed in order to be 95 percent confident that the sample proportion of respondents who said they took part in some sort of daily
Referring to Exercise 8.44, determine the sample size needed in order to be 99 percent confident that p̂, the sample proportion of ColorSmart-5000 television sets that last at least five years
Suppose we conduct a poll to estimate the proportion of voters who favor a major presidential candidate. Assuming that 50 percent of the electorate could be in favor of the candidate, determine the
Explain why the finite population correction√(N – n) / N is unnecessary when the sample size is less than 5 percent of the population size. Give an example using numbers.
A retailer that sells audio and video equipment accumulated 10,451 sales invoices during the previous year. The total of the sales amounts listed on these invoices (that is, the total sales claimed
A company’s manager is considering simplification of a travel voucher form. In order to assess the costs associated with erroneous travel vouchers, the manager must estimate the total number of
In an article in the Journal of Accounting Research, Ashton, Willingham, and Elliott studied audit delay (the length of time from a company’s fiscal year-end to the date of the auditor’s report)
In an article in Accounting and Business Research, Beattie and Jones investigate the use and abuse of graphic presentations in the annual reports of United Kingdom firms. The authors found that 65
National Motors has equipped the ZX-900 with a new disk brake system. We define the stopping distance for a ZX-900 to be the distance (in feet) required to bring the automobile to a complete stop
In an article in the Journal of Retailing, J. G. Blodgett, D. H. Granbois, and R. G. Walters investigated negative word-of-mouth consumer behavior. In a random sample of 201 consumers, 150 reported
A random sample of 50 perceived age estimates for a model in a cigarette advertisement showed that the sample mean and sample standard deviation were 26.22 years and 3.7432 years, respectively. a.
How safe are child car seats? Consumer Reports (May 2005) tested the safety of child car seats in 30 mph crashes. They found “slim safety margins” for some child car seats. Suppose that Consumer
Suppose that, for a sample of size n = 100 measurements, we find that x-bar = 50. Assuming that s equals 2, calculate confidence intervals for the population mean m with the following confidence
Consider the trash bag problem. Suppose that an independent laboratory has tested trash bags and has found that no 30- gallon bags that are currently on the market have a mean breaking strength of 50
Recall that a bank manager has developed a new system to reduce the time customers spend waiting to be served by tellers during peak business hours. The mean waiting time during peak business hours
The mean of the sample of 65 customer satisfaction ratings in Table 1.7 is 42.95. If we let m denote the mean of all possible customer satisfaction ratings for the XYZ Box video game system, and
Define each of the following: Type I error, α, Type II error, β.
Suppose that we wish to test H0: μ = 80 versus Ha: μ > 80, where the population standard deviation is known to equal 20. Also, suppose that a sample of 100 measurements randomly selected from
Suppose that we wish to test H0: μ = 20 versus Ha: μ < 20, where the population standard deviation is known to equal 7. Also, suppose that a sample of 49 measurements randomly selected from the
Suppose that we wish to test H0: μ = 40 versus Ha: μ ≠ 40, where the population standard deviation is known to equal 18. Also, suppose that a sample of 81 measurements randomly selected from the
Recall that “very satisfied” customers give the XYZ-Box video game system a rating that is at least 42. Suppose that the manufacturer of the XYZ-Box wishes to use the random sample of 65
Recall that a bank manager has developed a new system to reduce the time customers spend waiting for teller service during peak hours. The manager hopes the new system will reduce waiting times from
Consolidated Power, a large electric power utility, has just built a modern nuclear power plant. This plant discharges waste water that is allowed to flow into the Atlantic Ocean. The Environmental
Do part b of Exercise 9.15 if the sample mean equals 60.262. In par b exercise Suppose that Consolidated Power decides to use a level of significance of a .05, and suppose a random sample of 100
Do part b of Exercise 9.15 if the sample mean equals 60.618. In par b exercise Suppose that Consolidated Power decides to use a level of significance of a .05, and suppose a random sample of 100
An automobile parts supplier owns a machine that produces a cylindrical engine part. This part is supposed to have an outside diameter of three inches. Parts with diameters that are too small or too
The Crown Bottling Company has just installed a new bottling process that will fill 16- ounce bottles of the popular Crown Classic Cola soft drink. Both overfilling and underfilling bottles are
When testing a hypothesis, why don’t we set the probability of a Type I error to be extremely small? Explain.
National Motors has equipped the ZX-900 with a new disk brake system. We define m to be the mean stopping distance (from a speed of 35 mph) of all ZX-900s. National Motors would like to claim that
What assumptions must be met in order to carry out a t test about a population mean?
How do we decide whether to use a z test or a t test when testing a hypothesis about a population mean?
Suppose that a random sample of nine measurements from a normally distributed population gives a sample mean of 2.57 and a sample standard deviation of .3. Use critical values to test H0: μ = 3
Consider the e- billing case. The mean and the standard deviation of the sample of 65 payment times are 18.1077 and 3.9612, respectively.(1) Test H0: μ < 19.5 versus Ha: μ < 19.5 by setting a
Consider the trash bag case. The mean and the standard deviation of the sample of 40 trash bag breaking strengths are 50.575 and 1.6438, respectively.(1) Test H0: μ = 50 versus Ha: μ = 50 by
Recall that it is hoped that the mean alert time, m, using the new display panel is less than eight seconds.(1) Formulate the null hypothesis H0 and the alternative hypothesis Ha that would be used
The bad debt ratio for a financial institution is defined to be the dollar value of loans defaulted divided by the total dollar value of all loans made. Suppose that a random sample of seven Ohio
Recall that “very satisfied” customers give the XYZ-Box video game system a composite satisfaction rating that is at least 42.a. Letting m represent the mean composite satisfaction rating for the
Recall that “very satisfied” customers give the XYZ-Box video game system a rating that is at least 42. Suppose that the manufacturer of the XYZ-Box wishes to use the 65 satisfaction ratings to
Recall that a bank manager has developed a new system to reduce the time customers spend waiting for teller service during peak hours. The manager hopes the new system will reduce waiting times from
Consider a chemical company that wishes to determine whether a new catalyst, catalyst XA-100, changes the mean hourly yield of its chemical process from the historical process mean of 750 pounds per
Recall from Exercise 8.12 that Bayus (1991) studied the mean numbers of auto dealers visited by early and late replacement buyers.(1) Letting μ be the mean number of dealers visited by all late
In 1991 the average interest rate charged by U.S. credit card issuers was 18.8 percent. Since that time, there has been a proliferation of new credit cards affiliated with retail stores, oil
Suppose we test H0: p = .3 versus Ha: ≠ .3 and that a random sample of n = 100 gives a sample proportion p-bar = .20.a. Test H0 versus Ha at the .01 level of significance by using critical values.

Showing 16300 - 16400 of 88274

First
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
Last

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Secure Payment

Download Our App

© 2024 SolutionInn. All Rights Reserved