EMC EMC Certifications E20-007 Questions & Answers

• Question 61:

  A Data Scientist is assigned to build a model from a reporting data warehouse. The warehouse contains data collected from many sources and transformed through a complex, multi-stage ETL process. What is a concern the data scientist should have about the data?

  A. It is too processed

  B. It is not structured

  C. It is not normalized

  D. It is too centralized

  Correct Answer: A

• Question 62:

  Refer to the exhibit.

  

  You are building a decision tree. In this exhibit, four variables are listed with their respective values of info-gain.

  Based on this information, on which attribute would you expect the next split to be in the decision tree?

  A. Credit Score

  B. Age

  C. Income

  D. Gender

  Correct Answer: A

• Question 63:

  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 (gloves -> hat)?

  A. 75%

  B. 60%

  C. 66%

  D. 80%

  Correct Answer: A

• Question 64:

  A call center for a large electronics company handles an average of 35, 000 support calls a day. The head of the call center would like to optimize the staffing of the call center during the rollout of a new product due to recent customer complaints of long wait times. You have been asked to create a model to optimize call center costs and customer wait times.

  The goals for this project include:

  1.

  Relative to the release of a product, how does the call volume change over time?

  2.

  How to best optimize staffing based on the call volume for the newly released product, relative to old products.

  3.

  Historically, what time of day does the call center need to be most heavily staffed?

  4.

  Determine the frequency of calls by both product type and customer language. Which goals are suitable to be completed with MapReduce?

  A. Goal 2 and 4

  B. Goal 1 and 3

  C. Goals 1, 2, 3, 4

  D. Goals 2, 3, 4

  Correct Answer: A

• Question 65:

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

  A. generic functions

  B. virtual methods

  C. virtual functions

  D. generic methods

  Correct Answer: B

• Question 66:

  Which data asset is an example of quasi-structured data?

  A. Webserver log

  B. XML data file

  C. Database table

  D. News article

  Correct Answer: A

• Question 67:

  What is the reason for using LOESS?

  A. Fits a smoothed curve to scatterplot data; providing a general idea of the data's behavior

  B. Significance test for the correlation between two variables

  C. Plots a continuous variable versus a discrete variable; comparing distributions across classes

  D. Runs after a one-way ANOVA; determining which population has the highest mean value

  Correct Answer: A

• Question 68:

  In a Student's t-test, what is the meaning of the p-value?

  A. it is the area under the appropriate tails of the Student's distribution

  B. it is the "power" of the Student's t-test

  C. it is the mean of the distribution for the null hypothesis

  D. it is the mean of the distribution for the alternate hypothesis

  Correct Answer: A

• Question 69:

  How are window functions different from regular aggregate functions?

  A. Rows retain their separate identities and the window function can access more than the current row.

  B. Rows are grouped into an output row and the window function can access more than the current row.

  C. Rows retain their separate identities and the window function can only access the current row.

  D. Rows are grouped into an output row and the window function can only access the current row.

  Correct Answer: A

• Question 70:

  Which graphical representation shows the distribution and multiple summary statistics of a continuous variable for each value of a corresponding discrete variable?

  A. box and whisker plot

  B. dotplot

  C. scatterplot

  D. binplot

  Correct Answer: A