An assumption of linear regression states that for each value of X, there is a group of Y
values that are statistically __________________ and normally distributed about the
regression line.
A soap manufacturer is experimenting with several formulas of soap powder. Three of
the formulas were selected for further testing by a panel of homemakers. The ratings for
the three formulas are as follows:
The soap manufacturer decided to use the Kruskal-Wallis test. What is the null
hypothesis?
A statement about the value of a population parameter is called a ________________.
Twenty-one executives in a large corporation were randomly selected to study the effect
of several factors on annual salary (expressed in $000s). The factors selected were age,
seniority, years of college, number of company divisions they had been exposed to, and
the level of their responsibility. The results of the regression analysis follow:
Test the hypothesis that the regression coefficient for education is equal to 0 at the 0.05
significance level. Report the degrees of freedom, the critical value, the test statistic,
and your decision.
The paired difference test has ___________ degrees of freedom.
A population has a standard deviation of 25. We want to estimate the population mean
within 2, with a 95% level of confidence. How large a sample is required?
In a study of protein breakfast bars, five bars from each of three brands were tested to
see if the mean amount of protein per bar differs among the brands. If the brand sum of
squares is 0.07 and the error sum of squares is 0.09, the calculated value of F is _____.
A multiple regression model includes three independent variables: X1, X2, and (X1)(X2).
(X1)(X2) is called the ________________________.
A range chart shows the variation of ____________.
The following graph is used to evaluate an assumption of a multiple regression analysis.
What is the assumption?