EMC EMC Specialist E20-026 Questions & Answers

• Question 81:

  Data visualization is used in the final presentation of an analytics project. For what else is this technique commonly used?

  A. Assessing data quality

  B. Descriptive statistics

  C. ETLT

  D. Model selection

  Correct Answer: A

• Question 82:

  You have been assigned to do a study of the daily revenue effect of a pricing model of online transactions. All the data currently available to you has been loaded into your analytics database; revenue data, pricing data, and online transaction data. You find that all the data comes in different levels of granularity. The transaction data has timestamps (day, hour, minutes, seconds), pricing is stored at the daily level, and revenue data is only reported monthly. What is your next step?

  A. Report back to the business owner that the current data model does not support the business question.

  B. Interpolate a daily model for revenue from the monthly revenue data.

  C. Aggregate all data to the monthly level in order to create a monthly revenue model.

  D. Disregard revenue as a driver in the pricing model,and create a daily model based on pricing and transactions only.

  Correct Answer: A

• Question 83:

  Which SQL OLAP extension provides all possible grouping combinations?

  A. CUBE

  B. ROLLUP

  C. UNION ALL

  D. CROSS JOIN

  Correct Answer: A

• Question 84:

  What is the primary bottleneck in text classification?

  A. The availablilty of tagged training data.

  B. The ability to parse unstructured text data.

  C. The high dimensionality of text data.

  D. The fact that text corpora are dynamic.

  Correct Answer: A

• Question 85:

  What is required in a presentation for business analysts?

  A. Budgetary considerations and requests

  B. Operational process changes

  C. Detailed statistical explanation of the applicable modeling theory

  D. The presentation author's credentials

  Correct Answer: B

• Question 86:

  What is LOESS used for?

  A. It fits a smoothed curve to scatterplot data,to give a general sense of the data's behavior.

  B. It is a significance test for the correlation between two variables.

  C. It plots a continuous variable versus a discrete variable,to compare distributions across classes.

  D. It is run after a one-way ANOVA,to determine which population has the highest mean value.

  Correct Answer: A

• Question 87:

  Which process in text analysis can be used to reduce dimensionality?

  A. Stemming

  B. Parsing

  C. Digitizing

  D. Sorting

  Correct Answer: A

• Question 88:

  What is the format of the output from the Map function of MapReduce?

  A. Key-value pairs

  B. Binary respresentation of keys concatenated with structured data

  C. Compressed index

  D. Unique key record and separate records of all possible values

  Correct Answer: A

• Question 89:

  Which data type value is used for the observed response variable in a logistic regression model?

  A. Any positive real number

  B. Any integer

  C. A binary value

  D. Any real number

  Correct Answer: C

• Question 90:

  A data scientist is given an R data frame, "empdata", with the columns Age, Salary, Occupation, Education, and Gender. The data scientist would like to examine only the Salary and Occupation columns for ages greater than 40. Which command extracts the appropriate rows and columns from the data frame?

  A. empdata[empdata$Age > 40,c("Salary","Occupation")]

  B. empdata[c("Salary","Occupation"),empdata$Age > 40]

  C. empdata[Age > 40,("Salary","Occupation")]

  D. empdata[,c("Salary","Occupation")]$Age > 40

  Correct Answer: A