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
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Hire a Tutor
AI Study Help
New
Search
Search
Sign In
Register
study help
business
statistics for experimentert
Questions and Answers of
Statistics For Experimentert
10.2 For the following pairs, indicate which do not comply with the rules for setting up hypotheses, and explain why:a. H0: m 5 15, Ha: m 5 15b. H0: p 5 .4, Ha: p . .6c. H0: m 5 123, Ha: m , 123d.
10.1 Explain why the statement x 5 50 is not a legitimate hypothesis.
●● describe the effect of the significance level and the sample size on the power of a test.
●● carry out a t test for a population mean and interpret the results in context.
●● carry out a large-sample z test for a population proportion and interpret the results in context.
●● describe Type I and Type II errors in context.
●● translate a research question into null and alternative hypotheses.
●● the reasoning used to reach a decision in a hypothesis test.
●● why failing to reject the null hypothesis does not imply strong support for the null hypothesis.
●● that rejecting the null hypothesis implies strong support for the alternative hypothesis.
9.68 The interval from 22.33 to 1.75 captures an area of .95 under the z curve. This implies that another large-sample 95% confidence interval for m has lower limit x 2 2.33 sÏn and upper limit x 1
9.67 When n is large, the statistic s is approximately unbiased for estimating s and has approximately a normal distribution. The standard deviation of this statistic when the population distribution
9.66 The confidence intervals presented in this chapter give both lower and upper bounds on plausible values for the population characteristic being estimated.In some instances, only an upper bound
9.54 Authors of the news release titled “Major Gaps Still Exist Between the Perception and the Reality of Americans’ Internet Security Protections, Study Finds”(The National Cyber Security
9.51 The Bureau of Alcohol, Tobacco, and Firearms(BATF) has been concerned about lead levels in California wines. In a previous testing of wine specimens, lead levels ranging from 50 to 700 parts per
9.50 ● Five students visiting the student health center for a free dental examination during National Dental Hygiene Month were asked how many months had passed since their last visit to a dentist.
9.49 ● Fat content (in grams) for seven randomly selected hot dogs that were rated as very good by Consumer Reports (www.consumerreports.org) is shown below.Is it reasonable to use this data and
9.48 ● Example 9.3 gave the following airborne times(in minutes) for 10 randomly selected flights from San Francisco to Washington Dulles airport:270 256 267 285 274 275 266 258 271 281a. Compute
9.45 The article “The Association Between Television Viewing and Irregular Sleep Schedules Among Children Less Than 3 Years of Age” (Pediatrics [2005]: 851– 856)reported the accompanying 95%
9.42 The authors of the paper “Driven to Distraction”(Psychological Science [2001]: 462–466) describe an experiment to evaluate the effect of using a cell phone on reaction time. Subjects were
9.40 Medical research has shown that repeated wrist extensions beyond 20 degrees increase the risk of wrist and hand injuries. Each of 24 students at Cornell University used a proposed new computer
9.39 In a study of academic procrastination, the authors of the paper “Correlates and Consequences of Behavioral Procrastination” (Procrastination, Current Issues and New Directions [2000])
9.36 The two intervals (114.4, 115.6) and (114.1, 115.9)are confidence intervals (computed using the same sample data) for m 5 true average resonance frequency (in hertz) for all tennis rackets of a
9.35 The formula used to compute a confidence interval for the mean of a normal population when n is small is x 6 st critical valued sÏn What is the appropriate t critical value for each of the
9.34 Given a variable that has a t distribution with the specified degrees of freedom, what percentage of the time will its value fall in the indicated region?a. 10 df, between 21.81 and 1.81b. 10
9.33 Data from a survey of a representative sample was used to estimate that 32% of computer users in 2011 had tried to get on a Wi-Fi network that was not their own in order to save money (USA
9.25 The article “Viewers Speak Out Against Reality TV”(Associated Press, September 12, 2005) included the following statement: “Few people believe there’s much reality in reality TV: a total
9.16 In a survey on supernatural experiences, 722 of 4013 adult Americans surveyed reported that they had seen or been with a ghost (“What Supernatural Experiences We’ve Had,” USA Today,
9.15 Based on data from a survey of 1200 randomly selected Facebook users (USA Today, March 24, 2010), the following is a 90% confidence interval for the proportion of all Facebook users who say it
9.14 The article “Career Expert Provides DOs and DON’Ts for Job Seekers on Social Networking” (CareerBuilder.com, August 19, 2009) included data from a survey of 2667 hiring managers and human
9.13 Discuss how each of the following factors affects the width of the confidence interval for p. (Hint: Consider the confidence interval formula.)a. The confidence levelb. The sample sizec. The
9.11 The formula used to compute a large-sample confidence interval for p is p⁄6 sz critical valuedÎp⁄s1 2p⁄d nWhat is the appropriate z critical value for each of the following confidence
9.10 ▼ For each of the following choices, explain which would result in a wider large-sample confidence interval for p. (Hint: Consider the confidence interval formula.)a. 90% confidence level or
9.9 ● A random sample of 10 houses heated with natural gas in a particular area is selected, and the amount of gas (in therms) used during the month of January is determined for each house. The
9.8 ● A random sample of n 5 12 four-year-old red pine trees was selected, and the diameter (in inches) of each tree’s main stem was measured. The resulting observations are as follows:11.3 10.7
9.7 ● Given below are the sodium contents (in mg) for seven brands of hot dogs rated as “very good” by Consumer Reports (www.consumerreports.org):420 470 350 360 270 550 530a. Use the given
9.4 ● Data consistent with summary quantities in the article referenced in the previous exercise on total calorie consumption on a particular day are given for a sample of children who did not eat
9.3 Consumption of fast food is a topic of interest to researchers in the field of nutrition. The article “Effects of Fast-Food Consumption on Energy Intake and Diet Quality Among Children”
9.1 ▼ Three different statistics are being considered for estimating a population characteristic. The sampling distributions of the three statistics are shown in the following illustration:Which
●● determine the sample size necessary to achieve a desired bound on error when estimating a population proportion or a population mean.
●● the meaning of the confidence level associated with a confidence interval.Students will be able to:
●● the factors that affect the width of a confidence interval.
●● the relationships between sample size, margin of error, and the width of a confidence interval.
●● what it means for a statistic to be an unbiased estimator of a population characteristic.
8.37 The amount of money spent by a customer at a discount store has a mean of $100 and a standard deviation of $30. What is the probability that a randomly selected group of 50 shoppers will spend a
8.36 Suppose that 40% of all U.S. employees contribute to a retirement plan (p 5 .40).a. In a random sample of 100 employees, what is the approximate probability that at least half of those in the
8.32 The nicotine content in a single cigarette of a particular brand has a distribution with mean 0.8 mg and standard deviation 0.1 mg. If 100 randomly selected cigarettes of this brand are
8.30 Suppose that a particular candidate for public office is in fact favored by 48% of all registered voters in the district. A polling organization will take a random sample of 500 voters and will
8.28 The article “Should Pregnant Women Move? Linking Risks for Birth Defects with Proximity to Toxic Waste Sites” (Chance [1992]: 40– 45) reported that in a large study carried out in the
8.26 The article referenced in the previous exercise reported that for unmarried couples living together, the proportion that are racially or ethnically mixed is .15. Answer the questions posed in
8.25 ▼ The article “Unmarried Couples More Likely to Be Interracial”(San Luis Obispo Tribune, March 13, 2002) reported that 7% of married couples in the United States are mixed racially or
8.24a. For which of the sample sizes given in the previous exercise would the sampling distribution of p⁄be approximately normal if p 5 .65?b. For which of the sample sizes given in the previous
8.22 The thickness (in millimeters) of the coating applied to disk drives is one characteristic that determines the usefulness of the product. When no unusual circumstances are present, the thickness
8.21 ▼ An airplane with room for 100 passengers has a total baggage limit of 6000 pounds. Suppose that the total weight of the baggage checked by an individual passenger is a random variable x with
8.20 College students with checking accounts typically write relatively few checks in any given month, whereas adults who are not students typically write many more checks during a month. Suppose
8.19 A manufacturing process is designed to produce bolts with a 0.5-inch diameter. Once each day, a random sample of 36 bolts is selected and the bolt diameters are recorded. If the resulting sample
8.18 Suppose that a sample of size 100 is to be drawn from a population with standard deviation 10.a. What is the probability that the sample mean will be within 1 of the value of m?b. For this
8.17 Suppose that the mean value of interpupillary distance(the distance between the pupils of the left and right eyes) for adult males is 65 mm and that the population standard deviation is 5 mm.a.
8.16 In the library on a university campus, there is a sign in the elevator that indicates a limit of 16 persons.In addition, there is a weight limit of 2500 pounds.Assume that the average weight of
8.15 Let x denote the time (in minutes) that it takes a fifth-grade student to read a certain passage. Suppose that the mean value and standard deviation of x are m 5 2 minutes and s 5 0.8 minutes,
8.13 ▼ Suppose that a random sample of size 64 is to be selected from a population with mean 40 and standard deviation 5.a. What are the mean and standard deviation of the x sampling distribution?
8.12 Explain the difference between s and s x and between m and m x.
8.11 For which of the sample sizes given in the previous exercise would it be reasonable to think that the x sampling distribution is approximately normal in shape?
8.10 A random sample is selected from a population with mean m 5 100 and standard deviation s 5 10.Determine the mean and standard deviation of the x sampling distribution for each of the following
8.9 Consider the following population: {2, 3, 3, 4, 4}.The value of m is 3.2, but suppose that this is not known to an investigator. Three possible statistics for estimating m are Statistic 1: the
8.8 Simulate sampling from the population of Exercise 8.7 by using four slips of paper individually marked 1, 2, 3, and 4. Select a sample of size 2 without replacement, and compute x. Repeat this
8.7 ▼ Consider the following population: {1, 2, 3, 4}.For this population the mean is m 5 1 1 2 1 3 1 4 45 2.5 Suppose that a random sample of size 2 is to be selected without replacement from this
8.6 Suppose that the sampling experiment described in Example 8.1 had used samples of size 10 rather than size 5.a. If 50 samples of size 10 were selected, the x value for each sample computed, and a
8.5 Select 10 additional random samples of size 5 from the population of 20 students given in Example 8.1, and compute the mean amount spent on books for each of the 10 samples. Are the x values
8.4 Consider a population consisting of the following five values, which represent the number of DVD rentals during the academic year for each of five housemates:8 14 16 10 11a. Compute the mean of
8.2 What is the difference between x and m? between s and s?
8.1 Explain the difference between a population characteristic and a statistic.
●● use properties of the sampling distribution to reason informally about the value of a population mean or a population proportion.
● ● determine when the sampling distribution of x or p⁄is approximately normal.
● ● describe general properties of the sampling distribution of p⁄.
●● describe general properties of the sampling distribution of x.
● ● how the standard deviations of the sampling distributions of x and p⁄are related to sample size.
●● that sampling distribution describes sample-to-sample variability in the values of a statistic.
●● that the value of a sample statistic varies from sample to sample.
CR7.21 ● The following data are a sample of survival times (days from diagnosis) for patients suffering from chronic leukemia of a certain type:7 47 58 74 177 232 273 285 317 429 440 445 455 468
CR7.20 ● The paper “The Load-Life Relationship for M50 Bearings with Silicon Nitride Ceramic Balls” (Lubrication Engineering [1984]: 153–159) reported the accompanying data on bearing load
CR7.19 Consider the variable x 5 time required for a college student to complete a standardized exam Suppose that for the population of students at a particular university, the distribution of x is
CR7.18 A machine that produces ball bearings has initially been set so that the true average diameter of the bearings it produces is 0.500 inches. A bearing is acceptable if its diameter is within
CR7.17 An experiment was conducted to investigate whether a graphologist (a handwriting analyst) could distinguish a normal person’s handwriting from that of a psychotic.A well-known expert was
CR7.16 Return to the previous exercise, and let y denote the amount of material (in pounds) left after the next customer’s order is shipped. Find the mean and variance of y. (Hint: y is a linear
CR7.15 A chemical supply company currently has in stock 100 pounds of a certain chemical, which it sells to customers in 5-pound lots. Let x 5 the number of lots ordered by a randomly chosen
CR7.12 The article “Men, Women at Odds on Gun Control”(Cedar Rapids Gazette, September 8, 1999) included the following statement: “The survey found that 56% of American adults favored stricter
CR7.11 According to a study conducted by a risk assessment firm (Associated Press, December 8, 2005), drivers residing within 1 mile of a restaurant are 30% more likely to be in an accident in a
CR7.10 The Cedar Rapids Gazette (November 20, 1999)reported the following information on compliance with child restraint laws for cities in Iowa:City Number of Children Observed Number Properly
3. Doctors misdiagnosed heart attacks in 7% of women under 55 years old.Use the following event definitions:M 5 event that a heart attack is misdiagnosed, B 5 event that a patient is black, and W 5
2. Doctors misdiagnosed heart attacks in 4.3% of black patients.
1. Doctors misdiagnosed heart attacks in 2.1% of all patients.
CR7.9 The article “Doctors Misdiagnose More Women, Blacks” (San Luis Obispo Tribune, April 20, 2000) gave the following information, which is based on a large study of more than 10,000 patients
CR7.8 The paper “The Effect of Temperature and Humidity on Size of Segregated Traffic Exhaust Particle Emissions”(Atmospheric Environment [2008]: 2369–2382) gave the following summary
CR7.6 ● Manatees are large marine mammals found along the coast of Florida. Data on the total number of manatee deaths per year reported by the Florida Marine Research Center is given in the
CR7.5 Beverly is building a fireplace. She is using special decorative 8-inch bricks for the bottom row of the fireplace.Although the bricks are advertised as 8-inch bricks, the actual length of a
CR7.4 The following quote is from USA Today (January 21, 2010):Most Americans think the Census is important, and the majority say they will participate in the count this spring—although Hispanics,
CR7.3 Red-light cameras are used in many places to deter drivers from running red lights. The following graphical display is similar to one that appeared in the article “Communities Put a Halt to
CR7.2 ● The article “Water Consumption in the Bay Area”(San Jose Mercury News, January 16, 2010) reported the accompanying values for water consumption (gallons per person per day) for
7.126 There are approximately 40,000 travel agencies in the United States, of which 11,000 are members of the American Society of Travel Agents (booking a tour through an ASTA member increases the
Showing 1100 - 1200
of 4779
First
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Last