Question 1

Indicator variables can assume as many values as there are categories of its corresponding nominal variable.

Accepted Answer

Indicator variables, also known as dummy variables, are binary, assuming only two values (0 or 1) to represent the presence or absence of a category.

Question 2

The ____________________ variable of a regression model is the variable that you wish to analyze or predict.

Accepted Answer

The answer of The ____________________ variable of a regression model...

Question 3

If two indicator variables are used in a logistic regression model,then the nominal variable they represent has only two categories.

Accepted Answer

Indicator variables, also known as dummy variables, are used to encode categorical variables into a form that can be provided to machine learning algorithms. If two indicator variables are used, it implies that the nominal variable they represent has three categories. In general, if a nominal variable has N categories, N-1 indicator variables are needed to represent all categories.

Question 4

In stepwise regression,the independent variable with the largest F-statistic,or equally the smallest p-value,is chosen as the first entering variable.

Accepted Answer

In stepwise regression, the independent variable with the largest F-statistic or smallest p-value is chosen as the first entering variable. This is known as the forward selection method.

Question 5

If the odds ratio that an obese person who smokes 15 or more cigarettes per day suffers a heart attack is 9,then the probability that the person will suffer a heart attack is 0.81.

Accepted Answer

An odds ratio of 9 means that the odds of suffering a heart attack for an obese person who smokes 15 or more cigarettes per day are 9 times higher than the odds for those not in that category, not that the probability is 0.81 (or 81%). The odds ratio does not directly translate to probability without additional information.

Question 6

One of the requirements of regression analysis is that the dependent variable must be:
A)discrete.
B)continuous.
C)interval.
D)nominal.

Accepted Answer

The answer of One of the requirements of regression analysis...

Question 7

In stepwise regression procedure,the independent variable with the largest F-statistic,or equally with the smallest p-value,is chosen as the first entering variable.The standard,also called the F-to-enter,is usually set at F equals:
A)0
B)1
C)2
D)4

Accepted Answer

In stepwise regression, the F-to-enter value is typically set at 4, meaning a variable must have an F-statistic of at least 4 to be considered for entry into the model.

Question 8

In a multiple regression analysis,which procedure permits variables to enter and leave the model at different stages of its development?
A)Stepwise regression
B)Backward elimination
C)Residual analysis
D)Forward selection

Accepted Answer

Stepwise regression is a method that allows variables to enter and leave the model at different stages based on statistical criteria.

Question 9

The stepwise regression procedure begins by computing the simple regression model for each independent variable.

Accepted Answer

The stepwise regression procedure begins by computing the simple regression model for each independent variable and then selecting the variable that has the highest correlation with the dependent variable.

Question 10

In a stepwise regression procedure,if two independent variables are highly correlated,then:
A)neither variable will enter the equation.
B)both variables will enter the equation
C)only one variable will enter the equation.
D)not enough information is given to answer this question.

Accepted Answer

In stepwise regression, if two independent variables are highly correlated, only one variable will enter the equation since including both variables may cause multicollinearity issues and decrease the accuracy of the model. The algorithm will choose the variable that correlates better with the dependent variable to include in the equation.

Question 11

In building a regression model,it is best to use the ____________________ number of independent variables that produce a satisfactory model.

Accepted Answer

The answer of In building a regression model,it is best...

Question 12

At each step of the stepwise regression procedure,the p-values of all variables are computed and composed to the F-to-remove.If a variable's F-statistic falls below this standard,it is removed from the equation.

Accepted Answer

At each step of the stepwise regression procedure, the p-values of all variables are computed and compared to the F-to-remove value. If a variable's p-value exceeds this threshold, indicating that it is not statistically significant, it is removed from the equation. The F-statistic is not used to determine which variables to remove in stepwise regression.

Question 13

The stepwise regression procedure begins by computing the multiple regression model for all independent variables of interest.

Accepted Answer

Stepwise regression typically starts with an empty model and adds or removes variables one at a time based on specific criteria like the p-value, rather than beginning with a full model that includes all variables.

Question 14

____________________ regression is an iterative procedure that adds and deletes one independent variable at a time to/from the regression model.

Accepted Answer

The answer of ____________________ regression is an iterative procedure that...

Question 15

If the probability of an event is .20,then the odds ratio in favor of the event occurring is expressed as
A)1 to 4
B)1 to 3
C)1 to 2
D)1 to 1

Accepted Answer

To find the odds ratio in favor of an event occurring, we divide the probability of the event occurring by the probability of the event not occurring.

In this case, the probability of the event occurring is 0.20. The probability of the event not occurring is 1 - 0.20 = 0.80.

So, the odds ratio in favor of the event occurring is:

0.20 / 0.80 = 1/4

This can also be written as 1 to 4, meaning that for every one time the event occurs, it will not occur four times. Therefore, the correct answer is A) 1 to 4.

Question 16

When the dependent variable is nominal,a(n)____________________ regression model is used.

Accepted Answer

The answer of When the dependent variable is nominal,a(n)____________________ regression...

Question 17

Another name for an indicator variable is an interval variable.

Accepted Answer

An indicator variable is also known as a categorical variable or a binary variable, which takes on discrete values representing different categories or groups. In contrast, an interval variable is a type of quantitative variable where the distance between any two points is meaningful and equal.

Question 18

In stepwise regression,if two independent variables are highly correlated,both variables must enter the model simultaneously.

Accepted Answer

If two independent variables are highly correlated, stepwise regression may selectively omit one of them. This can occur if one variable has a lower significance level or if including both variables does not improve the overall model significantly.

Question 19

To gather the required observations for your potential regression models,a general rule is that there should be at least ____________________ observations for each independent variable used in the equation.

Accepted Answer

The answer of To gather the required observations for your...

Question 20

In stepwise regression the dependent variable must be ____________________.

Accepted Answer

The answer of In stepwise regression the dependent variable must...

Quiz 18: Model Building