Question: Estimate the mean and the standard deviation

> The manager of a computer software company wishes to study the number of hours per week senior executives by type of industry spend at their desktop computers. The manager selected a sample of five executives from each of three industries. At the .05 sig

> The following are six observations collected from treatment 1, four observations collected from treatment 2, and five observations collected from treatment 3. Test the hypothesis at the .05 significance level that the treatment means are equal. a. Stat

> Refer to the Baseball 2016 data, which report information on the 30 Major League Baseball teams for the 2016 season. a. At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus te

> A goal of financial literacy for children is to learn how to manage money wisely. One question is: How much money do children have to manage? A recent study by Schnur Educational Research Associates randomly sampled 15 children between 8 and 10 years old

> Businesses such as General Mills, Kellogg’s, and Betty Crocker regularly use coupons to build brand allegiance and stimulate sales. Marketers believe that the users of paper coupons are different from the users of e-coupons accessed through the Internet.

> Refer to the Lincolnville school bus data. Set up a variable that divides the age of the buses into three groups: new (less than 5 years old), medium (5 but less than 10 years), and old (10 or more years). The median maintenance cost is $4,179. Based on

> A computer manufacturer offers technical support that is available 24 hours a day, 7 days a week. Timely resolution of these calls is important to the company’s image. For 35 calls that were related to software, technicians resolved the issues in a mean

> The distribution of the number of viewers for the American Idol television show follows a normal distribution with a mean of 29 million and a standard deviation of 5 million. What is the probability next week’s show will: a. Have between 30 and 34 millio

> Refer to the North Valley Real Estate data, which report information on homes sold during the last year. a. Sort the data into a table that shows the number of homes that have a pool versus the number that don’t have a pool in each of the five townships.

> Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the night shift than on the day shift. The mean number of units produced by a sample of 54 day-shift workers was 345. The mean nu

> There are five sales associates at Mid-Motors Ford. The five associates and the number of cars they sold last week are: Sales Associate _________Cars Sold Peter Hankish ………………….………………. 8 Connie Stallter …………………………………. 6 Juan Lopez ……………………..………………. 4 Ted

> The federal government recently granted funds for a special program designed to reduce crime in high-crime areas. A study of the results of the program in eight high-crime areas of Miami, Florida, yielded the following results. Has there been a decreas

> The null and alternate hypotheses are: H0: μd = 0 H1: μd ≠ 0 The following paired observations show the number of traffic citations given for speeding by Officer Dhondt and Officer Meredith of the South Carol

> Refer to the Lincolnville School District bus data. Prepare a report on the maintenance cost for last month. Be sure to answer the following questions in your report. a. Around what values do the data tend to cluster? Specifically what was the mean maint

> Suppose you are an expert on the fashion industry and wish to gather information to compare the amount earned per month by models featuring Liz Claiborne attire with those of Calvin Klein. The following is the amount ($000) earned per month by a sample o

> Refer to the North Valley Real Estate data and prepare a report on the sales prices of the homes. Be sure to answer the following questions in your report. a. Around what values of price do the data tend to cluster? What is the mean sales price? What is

> The Tampa Bay (Florida) Area Chamber of Commerce wanted to know whether the mean weekly salary of nurses was larger than that of school teachers. To investigate, they collected the following information on the amounts earned last week by a sample of scho

> The following frequency distribution reports the electricity cost for a sample of 50 two-bedroom apartments in Albuquerque, New Mexico, during the month of May last year. Electricity Cost_____________Frequency $ 80 up to $100 ……………………………………….. 3 100 up

> In a marketing study, 100 consumers were asked to select the best digital music player from the iPod, the iRiver, and the Magic Star MP3. To summarize the consumer responses with a frequency table, how many classes would the frequency table have?

> A recent study compared the time spent together by single- and dual-earner couples. According to the records kept by the wives during the study, the mean amount of time spent together watching television among the single-earner couples was 61 minutes per

> The Kentucky Derby is held the first Saturday in May at Churchill Downs in Louisville, Kentucky. The race track is one and one-quarter miles. The following table shows the winners since 1990, their margin of victory, the winning time, and the payoff on a

> The null and alternate hypotheses are: H0: μ1 = μ2 H1: μ1 ≠ μ2 A random sample of 15 observations from the first population revealed a sample mean of 350 and a sample standard deviation of 12. A random sample of 17 observations from the second population

> A population consists of the following five values: 0, 0, 1, 3, 6. a. List all samples of size 3, and compute the mean of each sample. b. Compute the mean of the distribution of sample means and the population mean. Compare the two values. c. Compare the

> Creek Ratz is a very popular restaurant located along the coast of northern Florida. They serve a variety of steak and seafood dinners. During the summer beach season, they do not take reservations or accept “call aheadâ€&#15

> Refer to the Baseball 2016 data, which report information on the 30 Major League Baseball teams for the 2016 season. Assume the 2016 data represents a sample. a. Develop a 95% confidence interval for the mean number of home runs per team. b. Develop a 95

> Health issues are a concern of managers, especially as they evaluate the cost of medical insurance. A recent survey of 150 executives at Elvers Industries, a large insurance and financial firm located in the Southwest, reported the number of pounds by wh

> Refer to the Lincolnville School District bus data. a. Refer to the maintenance cost variable. The mean maintenance cost for last year is $4,552 with a standard deviation of $2332. Estimate the number of buses with a maintenance cost of more than $6,000.

> The weights (in pounds) of a sample of five boxes being sent by UPS are 12, 6, 7, 3, and 10. a. Compute the range. b. Compute the standard deviation.

> Near the time of an election, a cable news service performs an opinion poll of 1,000 probable voters. It shows that the Republican contender has an advantage of 52% to 48%. a. Develop a 95% confidence interval for the proportion favoring the Republican c

> The state of Maryland has license plates with three numbers followed by three letters. How many different license plates are possible?

> Refer to the North Valley Real Estate data, which report information on homes sold during the last year. a. The mean selling price (in $ thousands) of the homes was computed earlier to be $357.0, with a standard deviation of $160.7. Use the normal distri

> Refer to the Lincolnville School District bus data. Information provided by manufacturers of school buses suggests the mean maintenance cost per year is $4,400 per bus with a standard deviation of $1,000. Compute the mean maintenance cost for the Lincoln

> Refer to the North Valley Real Estate data, which report information on the homes sold last year. Assume the 105 homes is a population. Compute the population mean and the standard deviation of price. Select a sample of 10 homes. Compute the mean. Determ

> Suppose we roll a fair die two times. a. How many different samples are there? b. List each of the possible samples and compute the mean. c. On a chart similar to Chart 8–2, compare the distribution of sample means with the distribution of the population

> For the following situations, would you collect information using a sample or a population? Why? a. Statistics 201 is a course taught at a university. Professor Rauch has taught nearly 1,500 students in the course over the past 5 years. You would like to

> The Appliance Center has six sales representatives at its North Jacksonville outlet. The following table lists the number of refrigerators sold by each representative last month. a. How many samples of size 2 are possible? b. Select all possible sample

> At the downtown office of First National Bank, there are five tellers. Last week, the tellers made the following number of errors each: 2, 3, 5, 3, and 5. a. How many different samples of two tellers are possible? b. List all possible samples of size 2 a

> Trudy Green works for the True-Green Lawn Company. Her job is to solicit lawncare business via the telephone. Listed below is the number of appointments she made in each of the last 25 hours of calling. What is the arithmetic mean number of appointments

> The price of shares of Bank of Florida at the end of trading each day for the last year followed the normal distribution. Assume there were 240 trading days in the year. The mean price was $42.00 per share and the standard deviation was $2.25 per share.

> According to the “January theory,” if the stock market is up for the month of January, it will be up for the year. If it is down in January, it will be down for the year. According to an article in The Wall Street Journal, this theory held for 29 out of

> Reynolds Construction Company has agreed not to erect all “look-alike” homes in a new subdivision. Five exterior designs are offered to potential home buyers. The builder has standardized three interior plans that can be incorporated in any of the five e

> Cruise ships of the Royal Viking line report that 80% of their rooms are occupied during September. For a cruise ship having 800 rooms, what is the probability that 665 or more are occupied in September?

> Recent difficult economic times have caused an increase in the foreclosure rate of home mortgages. Statistics from the Penn Bank and Trust Company show their monthly foreclosure rate is now 1 loan out of every 136 loans. Last month the bank approved 300

> Suppose 1.5% of the antennas on new Nokia cell phones are defective. For a random sample of 200 antennas, find the probability that: a. None of the antennas is defective. b. Three or more of the antennas are defective.

> Advertising expenses are a significant component of the cost of goods sold. Listed below is a frequency distribution showing the advertising expenditures for 60 manufacturing companies located in the Southwest. Estimate the mean and the standard deviatio

> Listed below is the population by state for the 15 states with the largest population. Also included is whether that state’s border touches the Gulf of Mexico, the Atlantic Ocean, or the Pacific Ocean (coastline). Note that 5 of the 1

> A population consists of the following five values: 2, 2, 4, 4, and 8. a. List all samples of size 2, and compute the mean of each sample. b. Compute the mean of the distribution of sample means and the population mean. Compare the two values. c. Compare

> SCCoast, an Internet provider in the Southeast, developed the following frequency distribution on the age of Internet users. Estimate the mean and the standard deviation. Age (years) ___________Frequency 10 up to 20………………………………… 3 20 up to 30 …………………………

> DJ LeMahieu of the Colorado Rockies had the highest batting average in the 2016 Major League Baseball season. His average was .348. So assume the probability of getting a hit is .348 for each time he batted. In a particular game, assume he batted three t

> A recent news report indicated that 20% of all employees steal from their company each year. If a company employs 50 people, what is the probability that: a. Fewer than five employees steal? b. More than five employees steal? c. Exactly five employees st

> In establishing warranties on HDTVs, the manufacturer wants to set the limits so that few will need repair at the manufacturer’s expense. On the other hand, the warranty period must be long enough to make the purchase attractive to the buyer. For a new H

> Topten is a leading source on energy-efficient products. Their list of the top seven vehicles in terms of fuel efficiency for 2017 includes three Hondas. a. Determine the probability distribution for the number of Hondas in a sample of two cars chosen fr

> The website, herecomestheguide.com, suggested that couples planning their wedding should expect eighty percent of those who are sent an invitation to respond that they will attend. Rich and Stacy are planning to be married later this year. They plan to s

> Shorty’s Muffler advertises it can install a new muffler in 30 minutes or less. However, the work standards department at corporate headquarters recently conducted a study and found that 20% of the mufflers were not installed in 30 minutes or less. The M

> Dr. Richmond, a psychologist, is studying the daytime television viewing habits of college students. She believes 45% of college students watch soap operas during the afternoon. To further investigate, she selects a sample of 10. a. Develop a probability

> Refer to the Baseball 2016 data that report information on the 30 Major League Baseball teams for the 2016 season. Create a frequency distribution for the Team Salary variable and answer the following questions. a. What is the typical salary for a team?

> Assume a binomial probability distribution with n = 40 and π = .55. Compute the following: a. The mean and standard deviation of the random variable. b. The probability that x is 25 or greater. c. The probability that x is 15 or less. d. The probability

> Customers experiencing technical difficulty with their Internet cable service may call an 800 number for technical support. It takes the technician between 30 seconds and 10 minutes to resolve the problem. The distribution of this support time follows th

> Thirty percent of the population in a southwestern community are Spanish-speaking Americans. A Spanish-speaking person is accused of killing a non-Spanish-speaking American and goes to trial. Of the first 12 potential jurors, only 2 are Spanish-speaking

> The payouts for the Powerball lottery and their corresponding odds and probabilities of occurrence are shown below. The price of a ticket is $1.00. Find the mean and standard deviation of the payout. Hint: Don’t forget to include the co

> In the United States, the industrial revolution of the early 20th century changed farming by making it more efficient. For example, in 1910 U.S. farms used 24.2 million horses and mules and only about 1,000 tractors. By 1960, 4.6 million tractors were us

> An Internet company located in Southern California has season tickets to the Los Angeles Lakers basketball games. The company president always invites one of the four vice presidents to attend games with him, and claims he selects the person to attend at

> Refer to the Lincolnville School District bus data. a. Referring to the maintenance cost variable, develop a box plot. What are the minimum, first quartile, median, third quartile, and maximum values? Are there any outliers? b. Using the median maintenan

> The annual incomes of the five vice presidents of TMV Industries are $125,000; $128,000; $122,000; $133,000; and $140,000. Consider this a population. a. What is the range? b. What is the arithmetic mean income? c. What is the population variance? The st

> The following notice appeared in the golf shop at a Myrtle Beach, South Carolina, golf course. Blackmoor Golf Club Members The golf shop is holding a raffle to win a TaylorMade M1 10.5° Regular Flex Driver ($300 value). Tickets are $5.00 each. Only 80 ti

> Refer to the North Valley real estate data recorded on homes sold during the last year. Prepare a report on the selling prices of the homes based on the answers to the following questions. a. Compute the minimum, maximum, median, and the first and the th

> In a Poisson distribution μ = 4. a. What is the probability that x = 2? b. What is the probability that x ≤ 2? c. What is the probability that x > 2?

> A recent study of home technologies reported the number of hours of personal computer usage per week for a sample of 60 persons. Excluded from the study were people who worked out of their home and used the computer as a part of their work. a. Organize

> An investor owns three common stocks. Each stock, independent of the others, has equally likely chances of (1) Increasing in value, (2) Decreasing in value, or (3) Remaining the same value. List the possible outcomes of this experiment. Estimate the prob

> As part of a study of corporate employees, the director of human resources for PNC Inc. wants to compare the distance traveled to work by employees at its office in downtown Cincinnati with the distance for those in downtown Pittsburgh. A sample of 35 Ci

> Midland National Bank selected a sample of 40 student checking accounts. Below are their end-of-the-month balances. a. Tally the data into a frequency distribution using $100 as a class interval and $0 as the starting point. b. Draw a cumulative freque

> All eight companies in the aerospace industry were surveyed as to their return on investment last year. The results are: 10.6%, 12.6%, 14.8%, 18.2%, 12.0%, 14.8%, 12.2%, and 15.6%. Calculate the (a) Range, (b) Arithmetic mean, (c) Variance, and (d) Inter

> The Citizens Banking Company is studying the number of times the ATM located in a Loblaws Supermarket at the foot of Market Street is used per day. Following are the number of times the machine was used daily over each of the last 30 days. Determine the

> The numbers of outstanding shares for 24 publicly traded companies are listed in the following table. a. Using the number of outstanding shares, summarize the companies with a frequency distribution. b. Display the frequency distribution with a frequen

> The American Society of PeriAnesthesia Nurses (ASPAN; www.aspan.org) is a national organization serving nurses practicing in ambulatory surgery, preanesthesia, and postanesthesia care. The organization consists of the 40 components listed below. Use st

> The Department of Statistics at Western State University offers eight sections of basic statistics. Following are the numbers of students enrolled in these sections: 34, 46, 52, 29, 41, 38, 36, and 28. Calculate the (a) Range, (b) Arithmetic mean, (c) Va

> The information below shows the cost for a year of college in public and private colleges in 2002–03 and 2015–16. What is the geometric mean annual increase for the period for the two types of colleges? Compare the rat

> The monthly issues of the Journal of Finance are available on the Internet. The table below shows the number of times an issue was downloaded over the last 33 months. Suppose that you wish to summarize the number of downloads with a frequency distributio

> A study is made by the recording industry in the United States of the number of music CDs owned by 25 senior citizens and 30 young adults. The information is reported below. a. Find the median and the first and third quartiles for the number of CDs own

> David Wise handles his own investment portfolio, and has done so for many years. Listed below is the holding time (recorded to the nearest whole year) between purchase and sale for his collection of 36 stocks. a. How many classes would you propose? b.

> The top 25 companies (by market capitalization) operating in the Washington, DC, area along with the year they were founded and the number of employees are given below. Make a stem-and-leaf display of each of these variables and write a short description

> According to the Insurance Institute of America, a family of four spends between $400 and $3,800 per year on all types of insurance. Suppose the money spent is uniformly distributed between these amounts. a. What is the mean amount spent on insurance? b.

> The following data give the weekly amounts spent on groceries for a sample of 45 households. a. How many classes would you recommend? b. What class interval would you suggest? c. What would you recommend as the lower limit of the first class? d. Organi

> Owens Orchards sells apples in a large bag by weight. A sample of seven bags contained the following numbers of apples: 23, 19, 26, 17, 21, 24, 22. a. Compute the mean and median number of apples in a bag. b. Verify that Σ(x – x̅) = 0.

> As a part of their customer-service program, United Airlines randomly selected 10 passengers from today’s 9 a.m. Chicago–Tampa flight. Each sampled passenger will be interviewed about airport facilities, service, and so on. To select the sample, each pas

> Doctor’s Care is a walk-in clinic, with locations in Georgetown, Moncks Corner, and Aynor, at which patients may receive treatment for minor injuries, colds, and flu, as well as physical examinations. The following charts report the num

> Based on all student records at Camford University, students spend an average of 5.5 hours per week playing organized sports. The population’s standard deviation is 2.2 hours per week. Based on a sample of 121 students, Healthy Lifestyles Incorporated (H

> Speedy Swift is a package delivery service that serves the greater Atlanta, Georgia, metropolitan area. To maintain customer loyalty, one of Speedy Swift’s performance objectives is on-time delivery. To monitor its performance, each del

> The Medical Assurance Company is investigating the cost of a routine office visit to family-practice physicians in the Rochester, New York, area. The following is a list of 39 family-practice physicians in the region. Physicians are to be randomly select

> Answer the following questions in one or two well-constructed sentences. a. What happens to the standard error of the mean if the sample size is increased? b. What happens to the distribution of the sample means if the sample size is increased? c. When u

> Listed below are the salaries for the 2016 New York Yankees Major League Baseball team. a. Determine the mean, median, and the standard deviation. b. Determine the coefficient of skewness using Pearson’s method. c. Determine the coeff

> The frequency distribution of order lead time of the retailer from Exercise 18 is repeated below. Lead Time (days) __________Frequency 0 up to 5 …………….………………………………. 6 5 up to 10 …………………………………………... 7 10 up to 15 ………………………………………… 12 15 up to 20 ………………………

> The probability a D-Link network server is down is .05. If you have three independent servers, what is the probability that at least one of them is operational?

> Two components, A and B, operate in series. Being in series means that for the system to operate, both components A and B must work. Assume the two components are independent. What is the probability the system works under these conditions? The probabili

> What is the critical F value when the sample size for the numerator is four and the sample size for the denominator is seven? Use a one-tailed test and the .01 significance level.

> You need to estimate the mean number of travel days per year for salespeople. The mean of a small pilot study was 150 days, with a standard deviation of 14 days. If you must estimate the population mean within 2 days, how many salespeople should you samp

> A recent study by the American Automobile Dealers Association surveyed a random sample of 20 dealers. The data revealed a mean amount of profit per car sold was $290, with a standard deviation of $125. Develop a 95% confidence interval for the population

> The American Restaurant Association collected information on the number of meals eaten outside the home per week by young married couples. A survey of 60 couples showed the sample mean number of meals eaten outside the home was 2.76 meals per week, with

> Refer to the North Valley Real Estate data, which report information on homes sold in the area last year. Consider the following variables: selling price, number of bedrooms, township, and mortgage type. a. Which of the variables are qualitative and whic

> The following graph portrays the distribution of the number of spicy chicken sandwiches sold at a nearby Wendy’s for the last 141 days. The mean number of sandwiches sold per day is 91.9 and the standard deviation is 4.67. If we use t