E20-007 Online Practice Questions and Answers

Consider these itemsets:

(hat, scarf, coat)

(hat, scarf, coat, gloves)

(hat, scarf, gloves)

(hat, gloves)

(scarf, coat, gloves)

What is the confidence of the rule (hat, scarf) -> gloves?

A. 66%

B. 40%

C. 50%

D. 60%

In which lifecycle stage are initial hypotheses formed?

A. Discovery

B. Model planning

C. Model building

D. Data preparation

What does R code nv <- v[v < 1000] do?

A. Selects the values in vector v that are less than 1000 and assigns them to the vector nv

B. Sets nv to TRUE or FALSE depending on whether all elements of vector v are less than

C. Removes elements of vector v less than 1000 and assigns the elements >= 1000 to nv

D. Selects values of vector v less than 1000, modifies v, and makes a copy to nv

In linear regression, what indicates that an estimated coefficient is significantly different than zero?

A. A small p-value

B. R-squared near 1

C. R-squared near 0

D. The estimated coefficient is greater than 3

When is the GROUP BY ROLLUP clause used in an OLAP query?

A. All subtotals and grand totals are to be included in the output

B. Subtotals are only to be included in the output

C. Grand totals are only to be included in the output

D. Specific subtotals and grand totals for a combination of variables are only to be included in the output

You are using MADlib for Linear Regression analysis. Which value does the statement return? SELECT (linregr(depvar, indepvar)).r2 FROM zeta1;

A. Goodness of fit

B. Coefficients

C. Standard error

D. P-value

When creating a project sponsor presentation, what is the main objective?

A. Show that you met the project goals

B. Show how you met the project goals

C. Show how well the model will meet the SLA (service level agreement)

D. Clearly describe the methods and techniques used

In data visualization, which type of chart is recommended to represent frequency data?

A. Line chart

B. Histogram

C. Q-Q chart

D. Scatterplot

In R, functions like plot() and hist() are known as what?

A. generic functions

B. virtual methods

C. virtual functions

D. generic methods

You are building a logistic regression model to predict whether a tax filer will be audited within the next two years. Your training set population is 1000 filers. The audit rate in your training data is 4.2%. What is the sum of the probabilities that the model assigns to all the filers in your training set that have been audited?

A. 42.0

B. 4.2

C. 0.42

D. 0.042