- 8-4.1: Give three examples of proportions. Answers will vary.
- 8-4.2: Why is a proportion considered a binomial variable?
- 8-4.3: When you are testing hypotheses by using proportions, what are the ...
- 8-4.4: What are the mean and the standard deviation of a proportion? m _ n...
- 8-4.5: Home Ownership A recent survey found that 68.6% of the population o...
- 8-4.6: Stocks and Mutual Fund Ownership It has been found that 50.3% of U....
- 8-4.7: Overweight Children Health issues due to being overweight affect al...
- 8-4.8: Female Physicians The percentage of physicians who are women is 27....
- 8-4.9: Traveling Overseas Of U.S. residents traveling overseas, 47% were w...
- 8-4.10: Undergraduate Enrollment It has been found that 85.6% of all enroll...
- 8-4.11: Moviegoers The largest group of moviegoers by age is the 40- to 59-...
- 8-4.12: Exercise to Reduce Stress Asurvey by Mens Health magazine stated th...
- 8-4.13: After-School Snacks In the Journal of the American Dietetic Associa...
- 8-4.14: Natural Gas Heat The Energy Information Administration reported tha...
- 8-4.15: Youth Smoking Researchers suspect that 18% of all high school stude...
- 8-4.16: Television Set Ownership According to Nielsen Media Research, of al...
- 8-4.17: Borrowing Library Books For Americans using library services, the A...
- 8-4.18: Doctoral Students Salaries Nationally, at least 60% of Ph.D. studen...
- 8-4.19: Football Injuries Areport by the NCAAstates that 57.6% of football ...
- 8-4.20: Foreign Languages Spoken in Homes Approximately 19.4% of the U.S. p...
- 8-4.21: Coin Tossing A coin is tossed 9 times and 3 heads appear. Can you c...
- 8-4.22: First-Class Airline Passengers In the past, 20% of all airline pass...
- 8-4.23: Show that z _ can be derived from by substituting m _ np and s _ an...
Solutions for Chapter 8-4: z Test for a Proportion
Full solutions for Elementary Statistics: A Step by Step Approach 8th ed. | 8th Edition
A qualitative characteristic of an item or unit, usually arising in quality control. For example, classifying production units as defective or nondefective results in attributes data.
See Arithmetic mean.
An equation for a conditional probability such as PA B ( | ) in terms of the reverse conditional probability PB A ( | ).
Central composite design (CCD)
A second-order response surface design in k variables consisting of a two-level factorial, 2k axial runs, and one or more center points. The two-level factorial portion of a CCD can be a fractional factorial design when k is large. The CCD is the most widely used design for itting a second-order model.
Central limit theorem
The simplest form of the central limit theorem states that the sum of n independently distributed random variables will tend to be normally distributed as n becomes large. It is a necessary and suficient condition that none of the variances of the individual random variables are large in comparison to their sum. There are more general forms of the central theorem that allow ininite variances and correlated random variables, and there is a multivariate version of the theorem.
A subset selected without replacement from a set used to determine the number of outcomes in events and sample spaces.
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.
Completely randomized design (or experiment)
A type of experimental design in which the treatments or design factors are assigned to the experimental units in a random manner. In designed experiments, a completely randomized design results from running all of the treatment combinations in random order.
A graphical display used to monitor a process. It usually consists of a horizontal center line corresponding to the in-control 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 in-control, or free from assignable causes. Points beyond the control limits indicate an out-of-control process; that is, assignable causes are likely present. This signals the need to ind and remove the assignable causes.
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.
Degrees of freedom.
The number of independent comparisons that can be made among the elements of a sample. The term is analogous to the number of degrees of freedom for an object in a dynamic system, which is the number of independent coordinates required to determine the motion of the object.
A subset of effects in a fractional factorial design that deine the aliases in the design.
W. Edwards Deming (1900–1993) was a leader in the use of statistical quality control.
A matrix that provides the tests that are to be conducted in an experiment.
An experiment in which the tests are planned in advance and the plans usually incorporate statistical models. See Experiment
Discrete random variable
A random variable with a inite (or countably ininite) range.
The amount of variability exhibited by data
A subset of a sample space.
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.
In multiple regression, the matrix H XXX X = ( ) ? ? -1 . This a projection matrix that maps the vector of observed response values into a vector of itted values by yˆ = = X X X X y Hy ( ) ? ? ?1 .