 9.2.1: As the number of degrees of freedom in the tdistribution increases...
 9.2.2: True or False: The tdistribution is centered at m
 9.2.3: The notation ta is the tvalue such that the area under the tdistr...
 9.2.4: True or False: The value of t0.10 with 5 degrees of freedom is grea...
 9.2.5: True or False: To construct a confidence interval about the mean, t...
 9.2.6: The procedure for constructing a confidence interval about a mean i...
 9.2.7: (a) Find the tvalue such that the area in the right tail is 0.10 w...
 9.2.8: (a) Find the tvalue such that the area in the right tail is 0.02 w...
 9.2.9: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.10: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.11: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.12: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.13: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.14: In 914, a simple random sample of size n 6 30 has been obtained. Fr...
 9.2.15: In 1518, determine the point estimate of the population mean and ma...
 9.2.16: In 1518, determine the point estimate of the population mean and ma...
 9.2.17: In 1518, determine the point estimate of the population mean and ma...
 9.2.18: In 1518, determine the point estimate of the population mean and ma...
 9.2.19: A simple random sample of size n is drawn from a population that is...
 9.2.20: A simple random sample of size n is drawn from a population that is...
 9.2.21: A simple random sample of size n is drawn. The sample mean, x, is f...
 9.2.22: A simple random sample of size n is drawn. The sample mean, x, is f...
 9.2.23: You Explain It! Hours Worked In a survey conducted by the Gallup or...
 9.2.24: You Explain It! Sleeping A 90% confidence interval for the number o...
 9.2.25: You Explain It! DriveThrough Service Time The trade magazine QSR r...
 9.2.26: You Explain It! MySpace.com According to Nielsen/ NetRatings, the m...
 9.2.27: Hours Worked Revisited For the Hours Worked survey conducted by Gal...
 9.2.28: Sleeping Revisited Refer to the Sleeping results from 24. What coul...
 9.2.29: Blood Alcohol Concentration A random sample of 51 fatal crashes in ...
 9.2.30: Hungry or Thirsty? How much time do Americans spend eating or drink...
 9.2.31: How Much Do You Read? A recent Gallup poll asked 1006 Americans, Du...
 9.2.32: How Much Do You Read? A Gallup poll conducted July 21 August 14, 19...
 9.2.33: The SARS Epidemic Severe acute respiratory syndrome (SARS) is a vir...
 9.2.34: Tensile Strength Tensile strength is the amount of stress a materia...
 9.2.35: 4 GB Flash Memory Card After scanning the UPC code of a 4 GB flash ...
 9.2.36: Travel Taxes Travelers pay taxes for flying, car rentals, and hotel...
 9.2.37: Crash Test Results for Mini Cars The Insurance Institute for Highwa...
 9.2.38: Crawling Babies The following data represent the age (in weeks) at ...
 9.2.39: HarleyDavidson Stock Volume The trade volume of a stock is the num...
 9.2.40: PepsiCo Stock Volume The trade volume of a stock is the number of s...
 9.2.41: Sullivan Survey: Cell Phone Bills Treat the data obtained in the Su...
 9.2.42: Sullivan Survey: What Is Rich? Treat the data obtained in the Sulli...
 9.2.43: Age Married The 2006 General Social Survey asked respondents, If ev...
 9.2.44: Sexual Relations A question on the 2006 General Social Survey was t...
 9.2.45: Sample Size Dr. Paul Oswiecmiski wants to estimate the mean serum H...
 9.2.46: Sample Size Dr. Paul Oswiecmiski wants to estimate the mean serum H...
 9.2.47: Reading A recent Gallup poll asked Americans to disclose the number...
 9.2.48: Television A researcher wanted to determine the mean number of hour...
 9.2.49: Resistance and Robustness The data sets represent simple random sam...
 9.2.50: Effect of Outliers The following small data set represents a simple...
 9.2.51: Simulation: Normal Distribution IQ scores based on the Wechsler Int...
 9.2.52: Simulation: Exponential Distribution The exponential probability di...
 9.2.53: . Putting It Together: Smoking Cessation Study Researchers Havar Br...
 9.2.54: Putting It Together: How Many Drinks? A question on the General Soc...
 9.2.55: Explain why the tdistribution has less spread as the number of deg...
 9.2.56: The procedures for constructing a tinterval are robust. Explain wh...
 9.2.57: Explain what is meant by degrees of freedom.
 9.2.58: The mean age of the 43 presidents of the United States (as of 2011)...
 9.2.59: Suppose you have two populations: Population AAll students at Illin...
 9.2.60: Population A has standard deviation sA = 5, and population B has st...
Solutions for Chapter 9.2: ESTIMATING A POPULATION MEAN
Full solutions for Statistics: Informed Decisions Using Data  4th Edition
ISBN: 9780321757272
Solutions for Chapter 9.2: ESTIMATING A POPULATION MEAN
Get Full SolutionsChapter 9.2: ESTIMATING A POPULATION MEAN includes 60 full stepbystep solutions. This expansive textbook survival guide covers the following chapters and their solutions. Statistics: Informed Decisions Using Data was written by and is associated to the ISBN: 9780321757272. This textbook survival guide was created for the textbook: Statistics: Informed Decisions Using Data , edition: 4. Since 60 problems in chapter 9.2: ESTIMATING A POPULATION MEAN have been answered, more than 154611 students have viewed full stepbystep solutions from this chapter.

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).

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.

Binomial random variable
A discrete random variable that equals the number of successes in a ixed number of Bernoulli trials.

Bivariate normal distribution
The joint distribution of two normal random variables

C chart
An attribute control chart that plots the total number of defects per unit in a subgroup. Similar to a defectsperunit or U chart.

Chisquare test
Any test of signiicance based on the chisquare distribution. The most common chisquare tests are (1) testing hypotheses about the variance or standard deviation of a normal distribution and (2) testing goodness of it of a theoretical distribution to sample data

Comparative experiment
An experiment in which the treatments (experimental conditions) that are to be studied are included in the experiment. The data from the experiment are used to evaluate the treatments.

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

Conditional variance.
The variance of the conditional probability distribution of a random variable.

Consistent estimator
An estimator that converges in probability to the true value of the estimated parameter as the sample size increases.

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 .

Cumulative distribution function
For a random variable X, the function of X deined as PX x ( ) ? that is used to specify the probability distribution.

Dependent variable
The response variable in regression or a designed experiment.

Event
A subset of a sample space.

Expected value
The expected value of a random variable X is its longterm average or mean value. In the continuous case, the expected value of X is E X xf x dx ( ) = ?? ( ) ? ? where f ( ) x is the density function of the random variable X.

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.

Finite population correction factor
A term in the formula for the variance of a hypergeometric random variable.

Firstorder model
A model that contains only irstorder terms. For example, the irstorder response surface model in two variables is y xx = + ?? ? ? 0 11 2 2 + + . A irstorder model is also called a main effects model

Harmonic mean
The harmonic mean of a set of data values is the reciprocal of the arithmetic mean of the reciprocals of the data values; that is, h n x i n i = ? ? ? ? ? = ? ? 1 1 1 1 g .