Decision Making Quiz 5
A regression analysis between sales (in $1000) and advertising (in $) resulted in the following least squares line: = 32 + 8X. This implies that an increase of $1 in advertising is expected to result in an increase of $40 in sales.
false
In a nonlinear transformation of data, the Y variable or the X variables may be transformed, but not both.
false
In the multiple regression model we interpret X1 as follows: holding X2 constant, if X1 increases by 1 unit, then the expected value of Y will increase by 9 units.
false
Scatterplots are used for identifying outliers and quantifying relationships between variables.
false
The coefficients for logarithmically transformed explanatory variables should be interpreted as the percent change in the dependent variable for a 1% percent change in the explanatory variable.
false
Which of the following is an example of a nonlinear regression model? a.a quadratic regression equationb.a logarithmic regression equationc.constant elasticity equationd.the learning curve modele.all of these choices
all of these
The adjusted R2 adjusts R2 for:
the number of explanatory variables in a multiple regression model
In linear regression, a dummy variable is used:
to include categorical variables in the regression equation
A negative relationship between an explanatory variable X and a response variable Y means that as X increases, Y decreases, and vice versa.
true
A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least squares line: = 84 +7X. This implies that if there is no advertising, then the predicted amount of sales (in dollars) is $84,000.
true
A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least squares line: Y = 84 +7X. This implies that if advertising is $800, then the predicted amount of sales (in dollars) is $140,000.
true
A regression analysis between weight (Y in pounds) and height (X in inches) resulted in the following least squares line: = 140 + 5X. This implies that if the height is increased by 1 inch, the weight is expected to increase on average by 5 pounds.
true
Cross-sectional data are usually data gathered from approximately the same period of time from a cross-sectional of a population.
true
For the multiple regression model , if were to increase by 5 units, holding and constant, the value of Y would be expected to decrease by 50 units.
true
If a categorical variable is to be included in a multiple regression, a dummy variable for each category of the variable should be used, but the original categorical variables should not be used.
true
If the regression equation includes anything other than a constant plus the sum of products of constants and variables, the model will not be linear.
true
Regression analysis can be applied equally well to cross-sectional and time series data.
true
The adjusted R2 is used primarily to monitor whether extra explanatory variables really belong in a multiple regression model.
true
The primary purpose of a nonlinear transformation is to "straighten out" the data on a scatterplot.
true
The two primary objectives of regression analysis are to study relationships between variables and to use those relationships to make predictions.
true