- 2.2.1: Critical Thinking A personnel office is gathering data regarding wo...
- 2.2.2: Critical Thinking Your friend is thinking about buying shares of st...
- 2.2.3: Education: Does College Pay Off? It is costly in both time and mone...
- 2.2.4: Accidents: Child Deaths How safe is the world for kids? Unfortunate...
- 2.2.5: Commercial Fishing: Gulf of Alaska Its not an easy life, but its a ...
- 2.2.6: Archaeology: Ireland Commercial dredging operations in ancient rive...
- 2.2.7: Lifestyle: Hide the Mess! A survey of 1000 adults (reported in USA ...
- 2.2.8: Education: College Professors Time How do college professors spend ...
- 2.2.9: FBI Report: Hawaii In the Aloha state, you are very unlikely to be ...
- 2.2.10: Driving: Bad Habits Driving would be more pleasant if we didnt have...
- 2.2.11: Ecology: Lakes Pyramid Lake, Nevada, is described as the pride of t...
- 2.2.12: Vital Statistics: Height How does average height for boys change as...
Solutions for Chapter 2.2: Organizing Data
Full solutions for Understandable Statistics | 9th Edition
2 k p - factorial experiment
A fractional factorial experiment with k factors tested in a 2 ? p fraction with all factors tested at only two levels (settings) each
Adjusted R 2
A variation of the R 2 statistic that compensates for the number of parameters in a regression model. Essentially, the adjustment is a penalty for increasing the number of parameters in the model. Alias. In a fractional factorial experiment when certain factor effects cannot be estimated uniquely, they are said to be aliased.
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
Average run length, or ARL
The average number of samples taken in a process monitoring or inspection scheme until the scheme signals that the process is operating at a level different from the level in which it began.
Box plot (or box and whisker plot)
A graphical display of data in which the box contains the middle 50% of the data (the interquartile range) with the median dividing it, and the whiskers extend to the smallest and largest values (or some deined lower and upper limits).
The portion of the variability in a set of observations that is due to only random forces and which cannot be traced to speciic sources, such as operators, materials, or equipment. Also called a common cause.
A term used for the quantity ( / )( ) 1 1 2 n xi i n ? = that is subtracted from xi i n 2 ? =1 to give the corrected sum of squares deined as (/ ) ( ) 1 1 2 n xx i x i n ? = i ? . The correction factor can also be written as nx 2 .
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 off-diagonal elements rij are the correlations between Xi and Xj .
Another name for factors that are arranged in a factorial experiment.
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.
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.
Another name for a probability density function
Discrete random variable
A random variable with a inite (or countably ininite) range.
Discrete uniform random variable
A discrete random variable with a inite range and constant probability mass function.
Erlang random variable
A continuous random variable that is the sum of a ixed number of independent, exponential random variables.
A series of tests in which changes are made to the system under study
The distribution of the random variable deined as the ratio of two independent chi-square random variables, each divided by its number of degrees of freedom.
A signal from a control chart when no assignable causes are present
Fisher’s least signiicant difference (LSD) method
A series of pair-wise hypothesis tests of treatment means in an experiment to determine which means differ.
Goodness of fit
In general, the agreement of a set of observed values and a set of theoretical values that depend on some hypothesis. The term is often used in itting a theoretical distribution to a set of observations.