ISDS 2000
What is the predicted sales in millions of dollars for a company spending $100 mil on capital and $100 mil on wages?
$16,520.07
Which of the following values for the level of significance is the smallest for which the regression model as a whole is significant?
.001
Suppose the chemist decides to determine if there is a significant relationship btw time and dose. The p value of the test is
.011
Missing residual degrees of freedom are:
23
At the .01 level of significance, what conclusion should the macroeconomist draw regarding the inclusion of Capital in the regression model?
Capital is not significant in explaining corporate sales and should not be included in the model bc its p value is more than .01.
What should the macroeconomist who developed this multiple regression model be particularly concerned with?
Collinearity
In a multiple regression model, which of the following is correct regarding the value of the adjusted r^2?
It can be negative.
The F statistic for testing the entire regression model can be expressed as
MSR/MSE
The fitted model for predicting demand in LA is______
10+5x1
When two or more of the explanatory variables are highly correlated, this situation is referred to as:
Collinearity
The variance inflationary factor measures the:
Correlation of the X variables with each other.
Which of the following is not a residual plot that is typically used in multiple regression analysis?
Residuals vs Correlation coefficients
The coefficient of partial determination (r^2y1.2) for a multiple regression model containing only two independent variable is defined as:
SSR(X1|X2)/(SST-SSR(X1 and X2)+SSR(X1|X2))
Which of the independent variables in the model are individually significant at the 5% level?
Wages
The curvilinear model is one that contains which of the following "x"terms?
X^2
To test whether there is a location effect on demand, one would use:
a T TEST on the significance of B2.
Suppose the chemist decides to determine if there is a significant quadratic effect. the p-value of the test is:
.041
Suppose the macroeconomist wants to test whether the coefficient on capital is significantly different from 0. What is the value of the relevant t-stat?
.609
The centered curvilinear model obtained by MINITAB gives the predicted value of Y as
1283 +25.2 (Dose) + .860(Dose)^2
For a person receiving a dose of the drug that equals to 10 above the avg, the prediction of the time to relief is:
1621
The fitted model for predicting demand in San Fran is
18+5X1
Missing regression degrees of freedom is:
2
What fraction of the variability in sales is explained by spending on capital and wages?
68.9%
When the macroeconomist used a simple linear regression model with sales as the dependent variable and wages as the independent variable, he obtained an r^2 value of .601. What additional % of the total variation of sales has been explained by including the capital spending in the multiple regression?
8.8%
The contribution of an independent variable to a multiple regression model is measured by:
Both B + C
Using the natural log as a transformation allows you to change which of the following nonlinear models to a linear model?
Both b +c
Which of the following is NOT used to find a "best" model?
Durbin-Watson statistic
Referring to table 13-2, holding constant the effect of the city, easy additional increase of 1% in the mortgage rate would lead to an estimated avg ______ in the mean demand.
Increase of $500 per capita
The effect of living in San Fran rather than LA is ______ demanded by an estimated_______ holding the effect of mortgage rate constant.
Increase; $800 per capita
The coefficient of multiple determination r^2y.12:
Measures the proportion of variation in Y that is explained by X1 and X2.
The adjusted r^2 is "adjusted for" the:
Number of predictors and the sample size.
If a catagorical independent variable contains 2 categories, then________ dummy variables will be needed to uniquely represent these categories.
ONE
In order to calculate the efficient of multiple determination r^y.12, you would use which of the following formulas?
SSR/SST
In multiple regression, the _______ procedure permits variables to enter and leave the model at different stages of its development.
Stepwise Regression
To test for the significance of individual regression coefficients in a multiple regression model with more than 2 explanatory variables, you would use an
T TEST
In a multiple regression problem involving two independent variables, if b1 is computed to be +2.0, it means that
The estimated value of Y increases by an avg 2 unites for each increase of 1 unit of X1, holding X2 constant.
An interaction term in a multiple regression model may be used when:
The relationship between X1 and Y changes for differing values of X2.
A dummy variable is used as an independent variable in a regression model when:
The variable involved is categorical.
A regression diagnostic tool used to study the possible effects of collinearity is:
The variance inflationary factor.
How many degrees of freedom are associated with the multiple regression model when running a t-test for the individual coefficients?
n-p-1
