 8.R8.1: Conditions Martin says that the relative importance of the three co...
 8.R8.2: Its critical Find the appropriate critical value for constructing a...
 8.R8.3: Batteries A company that produces AA batteries tests the lifetime o...
 8.R8.4: We love football! A recent Gallup Poll conducted telephone intervie...
 8.R8.5: Smart kids A school counselor wants to know how smart the students ...
 8.R8.6: Do you go to church? The Gallup Poll plans to ask a random sample o...
 8.R8.7: Running red lights A random digit dialing telephone survey of 880 d...
 8.R8.8: Engine parts Here are measurements (in millimeters) of a critical d...
 8.R8.9: Good wood? A lab supply company sells pieces of Douglas fir 4 inche...
Solutions for Chapter 8: The Practice of Statistics 4th Edition
Full solutions for The Practice of Statistics  4th Edition
ISBN: 9781429245593
Solutions for Chapter 8
Get Full SolutionsThis expansive textbook survival guide covers the following chapters and their solutions. This textbook survival guide was created for the textbook: The Practice of Statistics, edition: 4. Since 9 problems in chapter 8 have been answered, more than 21760 students have viewed full stepbystep solutions from this chapter. Chapter 8 includes 9 full stepbystep solutions. The Practice of Statistics was written by and is associated to the ISBN: 9781429245593.

Alias
In a fractional factorial experiment when certain factor effects cannot be estimated uniquely, they are said to be aliased.

Axioms of probability
A set of rules that probabilities deined on a sample space must follow. See Probability

Biased estimator
Unbiased estimator.

Conidence coeficient
The probability 1?a associated with a conidence interval expressing the probability that the stated interval will contain the true parameter value.

Contingency table.
A tabular arrangement expressing the assignment of members of a data set according to two or more categories or classiication criteria

Continuous distribution
A probability distribution for a continuous random variable.

Continuous random variable.
A random variable with an interval (either inite or ininite) of real numbers for its range.

Correlation
In the most general usage, a measure of the interdependence among data. The concept may include more than two variables. The term is most commonly used in a narrow sense to express the relationship between quantitative variables or ranks.

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 .

Covariance matrix
A square matrix that contains the variances and covariances among a set of random variables, say, X1 , X X 2 k , , … . The main diagonal elements of the matrix are the variances of the random variables and the offdiagonal elements are the covariances between Xi and Xj . Also called the variancecovariance matrix. When the random variables are standardized to have unit variances, the covariance matrix becomes the correlation matrix.

Critical region
In hypothesis testing, this is the portion of the sample space of a test statistic that will lead to rejection of the null hypothesis.

Critical value(s)
The value of a statistic corresponding to a stated signiicance level as determined from the sampling distribution. For example, if PZ z PZ ( )( .) . ? =? = 0 025 . 1 96 0 025, then z0 025 . = 1 9. 6 is the critical value of z at the 0.025 level of signiicance. Crossed factors. Another name for factors that are arranged in a factorial experiment.

Deming
W. Edwards Deming (1900–1993) was a leader in the use of statistical quality control.

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

Dispersion
The amount of variability exhibited by data

Erlang random variable
A continuous random variable that is the sum of a ixed number of independent, exponential random variables.

Error of estimation
The difference between an estimated value and the true value.

Exhaustive
A property of a collection of events that indicates that their union equals the sample space.

False alarm
A signal from a control chart when no assignable causes are present

Forward selection
A method of variable selection in regression, where variables are inserted one at a time into the model until no other variables that contribute signiicantly to the model can be found.