- 8-2.1: Warming and Ice Melt The average depth of the Hudson Bay is 305 fee...
- 8-2.2: Credit Card Debt It has been reported that the average credit card ...
- 8-2.3: Revenue of Large Businesses Aresearcher estimates that the average ...
- 8-2.4: Moviegoers The average moviegoer sees 8.5 movies a year. A moviegoe...
- 8-2.5: Nonparental Care According to the Digest of Educational Statistics,...
- 8-2.6: Peanut Production inVirginia The average production of peanuts inVi...
- 8-2.7: Heights of 1-Year-Olds The average 1-year-old (both genders) is 29 ...
- 8-2.8: Salaries of Government Employees The mean salary of federal governm...
- 8-2.9: Operating Costs of an Automobile The average cost of owning and ope...
- 8-2.10: Home Prices in Pennsylvania Areal estate agent claims that the aver...
- 8-2.11: Use of Disposable Cups The average college student goes through 500...
- 8-2.12: Student Expenditures The average expenditure per student (based on ...
- 8-2.13: Ages of U.S. Senators The mean age of Senators in the 109th Congres...
- 8-2.14: What is meant by a P-value? The P-value is the actual probability o...
- 8-2.15: State whether the null hypothesis should be rejected on the basis o...
- 8-2.16: Soft Drink Consumption A researcher claims that the yearly consumpt...
- 8-2.17: Stopping Distances A study found that the average stopping distance...
- 8-2.18: Copy Machine Use A store manager hypothesizes that the average numb...
- 8-2.19: Burning Calories by Playing Tennis Ahealth researcher read that a 2...
- 8-2.20: Breaking Strength of Cable A special cable has a breaking strength ...
- 8-2.21: Farm Sizes The average farm size in the United States is 444 acres....
- 8-2.22: Farm Sizes Ten years ago, the average acreage of farms in a certain...
- 8-2.23: Transmission Service A car dealer recommends that transmissions be ...
- 8-2.24: Speeding Tickets A motorist claims that the South Boro Police issue...
- 8-2.25: Sick Days Amanager states that in his factory, the average number o...
- 8-2.26: Suppose a statistician chose to test a hypothesis at a _ 0.01. The ...
- 8-2.27: Hourly Wage The president of a company states that the average hour...
Solutions for Chapter 8-2: z Test for a Mean
Full solutions for Elementary Statistics: A Step by Step Approach 8th ed. | 8th Edition
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).
In a fractional factorial experiment when certain factor effects cannot be estimated uniquely, they are said to be aliased.
All possible (subsets) regressions
A method of variable selection in regression that examines all possible subsets of the candidate regressor variables. Eficient computer algorithms have been developed for implementing all possible regressions
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
Data consisting of counts or observations that can be classiied into categories. The categories may be descriptive.
Coeficient of determination
See R 2 .
Another term for the conidence coeficient.
A tabular arrangement expressing the assignment of members of a data set according to two or more categories or classiication criteria
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.
Continuous uniform random variable
A continuous random variable with range of a inite interval and a constant probability density function.
A linear function of treatment means with coeficients that total zero. A contrast is a summary of treatment means that is of interest in an experiment.
In hypothesis testing, this is the portion of the sample space of a test statistic that will lead to rejection of the null hypothesis.
A parameter in a tabular CUSUM algorithm that is determined from a trade-off between false alarms and the detection of assignable causes.
W. Edwards Deming (1900–1993) was a leader in the use of statistical quality control.
Discrete random variable
A random variable with a inite (or countably ininite) range.
Error mean square
The error sum of squares divided by its number of degrees of freedom.
Any test of signiicance involving the F distribution. The most common F-tests are (1) testing hypotheses about the variances or standard deviations of two independent normal distributions, (2) testing hypotheses about treatment means or variance components in the analysis of variance, and (3) testing signiicance of regression or tests on subsets of parameters in a regression model.
Fractional factorial experiment
A type of factorial experiment in which not all possible treatment combinations are run. This is usually done to reduce the size of an experiment with several factors.