Business Analysis Statistics Test #1

Question 1

A linear regression's usual formula is Y= beta0+beta1*X+error. Which phrase best encapsulates the presumptions made about the mistakes?

Accepted Answer

The errors are independent, normally distributed with zero mean and constant variance.

Answer

The errors are independent, normally distributed with constant mean and zero variance.

Answer

The errors are correlated, normally distributed with zero mean and constant variance.

Answer

The errors are correlated, normally distributed with constant mean and zero variance.

Question 2

Which SAS application will split the original data set into training and validation data sets stratified by county, each comprising 60% of the data?

Accepted Answer

Proc sort data=SASUSER.DATABASE;by county;run;proc surveyselect data=SASUSER.DATABASE samprate=0.6 out=sample outall;strata county;run;

Answer

Proc surveryselect data=SASUSER.DATABASE samprate=0.6 out=sample;strata country;run;

Answer

Proc sort data=SASUSER.DATABASE;by county;run;proc surveyselect data=SASUSER.DATABASE samprate=0.6 out=sample;strata county;eun;

Answer

Proc sort data=SASUSER.DATABASE;by county;run;proc surveyselect data=SASUSER.DATABASE samprate=0.6 out=sample outall;run;

Question 3

A logistic regression model's input variable, Region (A, B, or C), is investigated by an analyst. The analyst finds that when Region = A, the likelihood of purchasing a specific item is 1. What issue does this highlight?

Accepted Answer

Quasi-complete separation

Answer

Problems that arise due to missing values

Answer

Collinearity

Answer

Influential observations

Question 4

The mean incomes of men and women employed by a corporation are compared by an analyst. Variables in the SAS data collection SALARY include: Gender (M or F) Pay (dollars per year) What SAS tools may be used to calculate the p-value when comparing the wages of men and women? (Select two.)

Accepted Answer

Proc ttest data=salary;class gender;var pay;run;

Answer

Proc ttest data=salary;class gender;model pay=gender;run;

Answer

Proc glm data=salary;class pay;model pay=gender;run;

Question 5

Which statistic from a validation sample can be used to choose the model to employ for a binary target variable's prediction?

Accepted Answer

Average Squared Error

Answer

Adjusted R Square

Answer

Chi Square

Answer

Mallow's Cp

Question 6

Training, validation, and test data have been separated from the entire modeling data. Which data are most suitable for model evaluation?

Accepted Answer

Validation data

Answer

Test data

Answer

Training data

Answer

Total data

Question 7

Which statistic, when applied to a larger model, suggests a better model?

Accepted Answer

Adjusted R Square

Answer

Mallow's Cp

Answer

Average Squared Error

Answer

Chi Square

Question 8

Which of the following best defines a pair of observations that are incongruent in the LOGISTIC process?

Accepted Answer

In comparison to an observation without the event, an observation with the event has a lower anticipated probability.

Answer

There is an equal chance that one observation will be associated with the occurrence as another.

Answer

In comparison to an observation without the event, an observation with the event has a higher projected probability.

Answer

The anticipated probability for an observation with the event is the same as for an observation without the event.

Question 9

This model has been chosen as the winner by an analyst since it outperforms a rival model with more predictors in terms of model fit. Which statistic supports this argument?

Accepted Answer

Adj R-Sq

Answer

R-Square

Answer

Coeff Var

Answer

Error DF

Question 10

What is the best way to handle mean imputation when it is applied to data that has already been partitioned for an accurate assessment?

Accepted Answer

The validation and test data sets are subjected to the sample means from the training data set.

Answer

Each data partition's sample means are applied to that particular partition.

Answer

The training and validation data sets are adjusted using the sample means from the test data set.

Answer

The training and test data sets are subjected to the sample means from the validation data set.