QUESTIONS AND ANSWERS SURE A+
✔✔If a significant relationship exists between x and y and the coefficient of
determination shows that the fit is good, the estimated regression equation should be
useful for - ✔✔Estimation and prediction.
✔✔Larger values of r2 imply that the observations are more closely grouped about the -
✔✔Least squares line.
✔✔When constructing a confidence or a prediction interval to quantify the relationship
between two quantitative variables, what distribution do confidence and prediction
intervals follow? - ✔✔T distribution.
✔✔In a regression analysis, the error term ε is a random variable with a mean or
expected value of - ✔✔zero.
✔✔The tests of significance in regression analysis are based on assumptions about the
error term ɛ. One such assumption is that the values of ɛ are - ✔✔independent.
, ✔✔The tests of significance in regression analysis are based on assumptions about the
error term ɛ . One such assumption is that the variance of ɛ, denoted by 𝝈2, is - ✔✔The
same for all values of x.
✔✔An observation that has a strong influence or effect on the regression results is
called a(n) - ✔✔Influential observation.
✔✔Suppose a residual plot of x verses the residuals, y - ŷ, shows a nonconstant
variance. In particular, as the values of x increase, suppose that the values of the
residuals also increase. This means that - ✔✔as the values of x get larger, the ability to
predict y becomes less accurate.
✔✔The mathematical equation relating the independent variable to the expected value
of the dependent variable, E(y)=B0+b1x, is known as the - ✔✔regression equation.
✔✔When constructing a confidence or a prediction interval to quantify the relationship
between two quantitative variables, the appropriate degrees of freedom are - ✔✔n-2.
✔✔Influential observations always - ✔✔None of the above are correct
✔✔In a regression analysis, an outlier will always increase - ✔✔The value of the
correlation.
✔✔The tests of significance in regression analysis are based on assumptions about the
error term ɛ. One such assumption is that the error term follows ɛ a(n) _____ distribution
for all values of x. - ✔✔Normal.
✔✔In regression analysis, the variable that is being predicted is the - ✔✔dependent
variable.
✔✔An F test, based on the F probability distribution, can be used to test for -
✔✔Significance in regression.
✔✔Which of the following statements is false? - ✔✔Regression analysis can be
interpreted as aprocedure for establishing a cause-and-effect relationship between
variables.
✔✔A graph of the standardized residuals plotted against values of the normal scores
that helps to determine whether the assumption that the error term has a normal
probability distribution appears to be valid is called a - ✔✔Normal probability plot