 Chapter 9.1: A sample of 49 observations is taken from a normal population with ...
 Chapter 9.2: A sample of 81 observations is taken from a normal population with ...
 Chapter 9.3: A sample of 250 observations is selected from a normal population f...
 Chapter 9.4: Suppose you know and you want an 85 percent confidence level. What ...
 Chapter 9.5: A research firm conducted a survey to determine the mean amount ste...
 Chapter 9.6: Refer to the previous exercise. Suppose that 64 smokers (instead of...
 Chapter 9.7: Bob Nale is the owner of Nales Quick Fill. Bob would like to estima...
 Chapter 9.8: Dr. Patton is a professor of English. Recently she counted the numb...
 Chapter 9.9: Use Appendix B.2 to locate the value of t under the following condi...
 Chapter 9.10: Use Appendix B.2 to locate the value of t under the following condi...
 Chapter 9.11: The owner of Brittens Egg Farm wants to estimate the mean number of...
 Chapter 9.12: The U.S. Dairy Industry wants to estimate the mean yearly milk cons...
 Chapter 9.13: Merrill Lynch Securities and Health Care Retirement Inc. are two la...
 Chapter 9.14: The Greater Pittsburgh Area Chamber of Commerce wants to estimate t...
 Chapter 9.15: The owner of the West End Kwick Fill Gas Station wishes to determin...
 Chapter 9.16: Ms. Maria Wilson is considering running for mayor of the town of Be...
 Chapter 9.17: The Fox TV network is considering replacing one of its primetime c...
 Chapter 9.18: Schadek Silkscreen Printing Inc. purchases plastic cups on which to...
 Chapter 9.19: A population is estimated to have a standard deviation of 10. We wa...
 Chapter 9.20: We want to estimate the population mean within 5, with a 99 percent...
 Chapter 9.21: The estimate of the population proportion is to be within plus or m...
 Chapter 9.22: The estimate of the population proportion is to be within plus or m...
 Chapter 9.23: A survey is being planned to determine the mean amount of time corp...
 Chapter 9.24: A processor of carrots cuts the green top off each carrot, washes t...
 Chapter 9.25: Suppose the U.S. president wants an estimate of the proportion of t...
 Chapter 9.26: Past surveys reveal that 30 percent of tourists going to Las Vegas ...
 Chapter 9.27: Thirtysix items are randomly selected from a population of 300 ite...
 Chapter 9.28: Fortynine items are randomly selected from a population of 500 ite...
 Chapter 9.29: The attendance at the Savannah Colts minor league baseball game las...
 Chapter 9.30: There are 300 welders employed at Maine Shipyards Corporation. A sa...
 Chapter 9.31: A random sample of 85 group leaders, supervisors, and similar perso...
 Chapter 9.32: A state meat inspector in Iowa has been given the assignment of est...
 Chapter 9.33: As part of their business promotional package, the Milwaukee Chambe...
 Chapter 9.34: A recent survey of 50 executives who were laid off during a recent ...
 Chapter 9.35: Marty Rowatti recently assumed the position of director of the YMCA...
 Chapter 9.36: The American Restaurant Association collected information on the nu...
 Chapter 9.37: The American Restaurant Association collected information on the nu...
 Chapter 9.38: The Human Relations Department of Electronics Inc. would like to in...
 Chapter 9.39: A student conducted a study and reported that the 95 percent confid...
 Chapter 9.40: A recent study by the American Automobile Dealers Association revea...
 Chapter 9.41: A study of 25 graduates of fouryear colleges by the American Banke...
 Chapter 9.42: An important factor in selling a residential property is the number...
 Chapter 9.43: Warren County Telephone Company claims in its annual report that th...
 Chapter 9.44: The manufacturer of a new line of inkjet printers would like to in...
 Chapter 9.45: Dr. Susan Benner is an industrial psychologist. She is currently st...
 Chapter 9.46: As a condition of employment, Fashion Industries applicants must pa...
 Chapter 9.47: Fashion Industries randomly tests its employees throughout the year...
 Chapter 9.48: During a national debate on changes to health care, a cable news se...
 Chapter 9.49: There are 20,000 eligible voters in York County, South Carolina. A ...
 Chapter 9.50: In a poll to estimate presidential popularity, each person in a ran...
 Chapter 9.51: Police Chief Edward Wilkin of River City reports 500 traffic citati...
 Chapter 9.52: The First National Bank of Wilson has 650 checking account customer...
 Chapter 9.53: It is estimated that 60 percent of U.S. households subscribe to cab...
 Chapter 9.54: You need to estimate the mean number of travel days per year for ou...
 Chapter 9.55: You are to conduct a sample survey to determine the mean family inc...
 Chapter 9.56: Families USA, a monthly magazine that discusses issues related to h...
 Chapter 9.57: Passenger comfort is influenced by the amount of pressurization in ...
 Chapter 9.58: A random sample of 25 people employed by the Florida state authorit...
 Chapter 9.59: A film alliance used a random sample of 50 U.S. citizens to estimat...
 Chapter 9.60: Dylan Jones kept careful records of the fuel efficiency of his new ...
 Chapter 9.61: A survey of 36 randomly selected iPhone owners showed that the purc...
 Chapter 9.62: You plan to conduct a survey to find what proportion of the workfor...
 Chapter 9.63: The proportion of public accountants who have changed companies wit...
 Chapter 9.64: As part of an annual review of its accounts, a discount brokerage s...
 Chapter 9.65: The National Weight Control Registry tries to mine secrets of succe...
 Chapter 9.66: Near the time of an election, a cable news service performs an opin...
 Chapter 9.67: A sample of 352 subscribers to Wired magazine shows the mean time s...
 Chapter 9.68: The Tennessee Tourism Institute (TTI) plans to sample information c...
 Chapter 9.69: Refer to the Real Estate data, which report information on homes so...
 Chapter 9.70: Refer to the Baseball 2009 data, which report information on the 30...
 Chapter 9.71: Refer to the Buena School District bus data. a. Develop a 95 percen...
Solutions for Chapter Chapter 9: Estimation and Confidence Intervals
Full solutions for Statistical Techniques in Business and Economics  15th Edition
ISBN: 9780073401805
Solutions for Chapter Chapter 9: Estimation and Confidence Intervals
Get Full SolutionsThis expansive textbook survival guide covers the following chapters and their solutions. Since 71 problems in chapter Chapter 9: Estimation and Confidence Intervals have been answered, more than 27086 students have viewed full stepbystep solutions from this chapter. This textbook survival guide was created for the textbook: Statistical Techniques in Business and Economics, edition: 15. Statistical Techniques in Business and Economics was written by and is associated to the ISBN: 9780073401805. Chapter Chapter 9: Estimation and Confidence Intervals includes 71 full stepbystep solutions.

Addition rule
A formula used to determine the probability of the union of two (or more) events from the probabilities of the events and their intersection(s).

Arithmetic mean
The arithmetic mean of a set of numbers x1 , x2 ,…, xn is their sum divided by the number of observations, or ( / )1 1 n xi t n ? = . The arithmetic mean is usually denoted by x , and is often called the average

Bayes’ estimator
An estimator for a parameter obtained from a Bayesian method that uses a prior distribution for the parameter along with the conditional distribution of the data given the parameter to obtain the posterior distribution of the parameter. The estimator is obtained from the posterior distribution.

Chance cause
The portion of the variability in a set of observations that is due to only random forces and which cannot be traced to speciic sources, such as operators, materials, or equipment. Also called a common cause.

Combination.
A subset selected without replacement from a set used to determine the number of outcomes in events and sample spaces.

Conditional probability density function
The probability density function of the conditional probability distribution of a continuous random variable.

Conditional probability distribution
The distribution of a random variable given that the random experiment produces an outcome in an event. The given event might specify values for one or more other random variables

Conidence interval
If it is possible to write a probability statement of the form PL U ( ) ? ? ? ? = ?1 where L and U are functions of only the sample data and ? is a parameter, then the interval between L and U is called a conidence interval (or a 100 1( )% ? ? conidence interval). The interpretation is that a statement that the parameter ? lies in this interval will be true 100 1( )% ? ? of the times that such a statement is made

Contour plot
A twodimensional graphic used for a bivariate probability density function that displays curves for which the probability density function is constant.

Control chart
A graphical display used to monitor a process. It usually consists of a horizontal center line corresponding to the incontrol value of the parameter that is being monitored and lower and upper control limits. The control limits are determined by statistical criteria and are not arbitrary, nor are they related to speciication limits. If sample points fall within the control limits, the process is said to be incontrol, or free from assignable causes. Points beyond the control limits indicate an outofcontrol process; that is, assignable causes are likely present. This signals the need to ind and remove the assignable causes.

Cook’s distance
In regression, Cook’s distance is a measure of the inluence of each individual observation on the estimates of the regression model parameters. It expresses the distance that the vector of model parameter estimates with the ith observation removed lies from the vector of model parameter estimates based on all observations. Large values of Cook’s distance indicate that the observation is inluential.

Correlation matrix
A square matrix that contains the correlations among a set of random variables, say, XX X 1 2 k , ,…, . The main diagonal elements of the matrix are unity and the offdiagonal elements rij are the correlations between Xi and Xj .

Crossed factors
Another name for factors that are arranged in a factorial experiment.

Cumulative normal distribution function
The cumulative distribution of the standard normal distribution, often denoted as ?( ) x and tabulated in Appendix Table II.

Defect
Used in statistical quality control, a defect is a particular type of nonconformance to speciications or requirements. Sometimes defects are classiied into types, such as appearance defects and functional defects.

Designed experiment
An experiment in which the tests are planned in advance and the plans usually incorporate statistical models. See Experiment

Distribution function
Another name for a cumulative distribution function.

Estimate (or point estimate)
The numerical value of a point estimator.

Estimator (or point estimator)
A procedure for producing an estimate of a parameter of interest. An estimator is usually a function of only sample data values, and when these data values are available, it results in an estimate of the parameter of interest.

F distribution.
The distribution of the random variable deined as the ratio of two independent chisquare random variables, each divided by its number of degrees of freedom.