- 7-1.1: What is the difference between a point estimate and an interval est...
- 7-1.2: What information is necessary to calculate a confidence interval?
- 7-1.3: What is the margin of error?
- 7-1.4: What is meant by the 95% confidence interval of the mean?
- 7-1.5: What are three properties of a good estimator? A good estimator sho...
- 7-1.6: What statistic best estimates m?
- 7-1.7: What is necessary to determine the sample size?
- 7-1.8: In determining the sample size for a confidence interval, is the si...
- 7-1.9: Find each. a. za_2 for the 99% confidence interval 2.58 b. za_2 for...
- 7-1.10: Number of Faculty The numbers of faculty at 32 randomly selected st...
- 7-1.11: Playing Video Games In a recent study of 35 ninthgrade students, th...
- 7-1.12: Freshmens GPA First-semester GPAs for a random selection of freshme...
- 7-1.13: Workers Distractions A recent study showed that the modern working ...
- 7-1.14: Number of Jobs A sociologist found that in a sample of 50 retired m...
- 7-1.15: Actuary Exams A survey of 35 individuals who passed the seven exams...
- 7-1.16: Number of Farms A random sample of the number of farms (in thousand...
- 7-1.17: TelevisionViewing Astudy of 415 kindergarten students showed that t...
- 7-1.18: Day Care Tuition Arandom sample of 50 four-year-olds attending day ...
- 7-1.19: Hospital Noise Levels Noise levels at various area urban hospitals ...
- 7-1.20: Length of Growing Seasons The growing seasons for a random sample o...
- 7-1.21: Convenience Store Shoppers A random sample of shoppers at a conveni...
- 7-1.22: In the hospital study cited in Exercise 19, the mean noise level in...
- 7-1.23: Birth Weights of Infants A health care professional wishes to estim...
- 7-1.24: Cost of Pizzas Apizza shop owner wishes to find the 95% confidence ...
- 7-1.25: National Accounting Examination If the variance of a national accou...
- 7-1.26: Commuting Times in New York The 90% confidence interval for the mea...
Solutions for Chapter 7-1: Confidence Intervals for the Mean When s Is Known
Full solutions for Elementary Statistics: A Step by Step Approach 8th ed. | 8th Edition
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
The portion of the variability in a set of observations that can be traced to speciic causes, such as operators, materials, or equipment. Also called a special cause.
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.
A method of variable selection in regression that begins with all of the candidate regressor variables in the model and eliminates the insigniicant regressors one at a time until only signiicant regressors remain
Chi-square (or chi-squared) random variable
A continuous random variable that results from the sum of squares of independent standard normal random variables. It is a special case of a gamma random variable.
Any test of signiicance based on the chi-square distribution. The most common chi-square 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
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.
A measure of association between two random variables obtained as the expected value of the product of the two random variables around their means; that is, Cov(X Y, ) [( )( )] =? ? E X Y ? ? X Y .
A parameter in a tabular CUSUM algorithm that is determined from a trade-off between false alarms and the detection of assignable causes.
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.
Defect concentration diagram
A quality tool that graphically shows the location of defects on a part or in a process.
Discrete uniform random variable
A discrete random variable with a inite range and constant probability mass function.
Another name for a cumulative distribution function.
A concept in parameter estimation that uses the variances of different estimators; essentially, an estimator is more eficient than another estimator if it has smaller variance. When estimators are biased, the concept requires modiication.
A model that contains only irstorder terms. For example, the irst-order response surface model in two variables is y xx = + ?? ? ? 0 11 2 2 + + . A irst-order model is also called a main effects model
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.
A function used in the probability density function of a gamma random variable that can be considered to extend factorials
Another name for the normal distribution, based on the strong connection of Karl F. Gauss to the normal distribution; often used in physics and electrical engineering applications
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 .
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