EMC EMC Certifications E20-007 Questions & Answers

• Question 151:

  When is a Wilcoxon Rank-Sum test used?

  A. When an assumption about the distribution of the populations cannot be made

  B. When the data can be easily sorted

  C. When the populations represent the sums of other values

  D. When the data cannot be easily sorted

  Correct Answer: A

• Question 152:

  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%

  Correct Answer: A

• Question 153:

  Refer to the exhibit.

  

  You have scored your Naive bayesian classifier model on a hold out test data for cross validation and

  determined the way the samples scored and tabulated them as shown in the exhibit.

  What are the the False Positive Rate (FPR) and the False Negative Rate (FNR) of the model?

  A. FPR = 15/262 FNR = 26/288

  B. FPR = 26/288 FNR = 15/262

  C. FPR = 262/15 FNR = 288/26

  D. FPR = 288/26 FNR = 262/15

  Correct Answer: A

• Question 154:

  You have been assigned to run a linear regression model for each of 5, 000 distinct districts, and all the data is currently stored in a PostgreSQL database. Which tool/library would you use to produce these models with the least effort?

  A. MADlib

  B. Mahout

  C. R

  D. HBase

  Correct Answer: A

• Question 155:

  While having a discussion with your colleague, this person mentions that they want to perform K-means clustering on text file data stored in HDFS.

  Which tool would you recommend to this colleague?

  A. Mahout

  B. HBase

  C. Scribe

  D. Sqoop

  Correct Answer: A

• Question 156:

  You are studying the behavior of a population and are provided with multi-dimensional data at the individual level. You have identified four specific individuals who are valuable to your study. You would like to find all users who are most similar to each individual.

  Which algorithm is most appropriate for this study?

  A. K-means clustering

  B. Linear regression

  C. Association rules

  D. Decision trees

  Correct Answer: A

• Question 157:

  Refer to the exhibit.

  

  After analyzing a dataset, you report findings to your team:

  1.

  Variables A and C are significantly and positively impacting the dependent variable.

  2.

  Variable B is significantly and negatively impacting the dependent variable.

  3.

  Variable D is not significantly impacting the dependent variable.

  After seeing your findings, the majority of your team agreed that variable B should be positively impacting

  the dependent variable.

  What is a possible reason the coefficient for variable B was negative and not positive?

  A. Variable B is interacting with another variable due to correlated inputs

  B. Variable B needs a quadratic transformation due to its relationship to the dependent variable

  C. The information gain from variable B is already provided by another variable

  D. Variable B needs a logarithmic transformation due to its relationship to the dependent variable

  Correct Answer: A

• Question 158:

  Refer to the exhibit.

  

  You ran a linear regression, and the final output is seen in the exhibit.

  Based only on the information in the exhibit and an acceptable confidence level of 95%, how would you interpret the interaction of variable D with the dependent variable?

  A. In this model, Variable D is not significantly interacting with the dependent variable

  B. For every 1 unit increase in variable D, holding all other variables constant, we can expect the dependent variable to increase by 10.23 units

  C. For every 1 unit increase in variable D, holding all other variables constant, we can expect the dependent variable to be multiplied by 10.23 units

  D. Variable D is more significant than variables A, B, and C.

  Correct Answer: A

• Question 159:

  You submit a MapReduce job to a Hadoop cluster. However, you notice that although the job was

  successfully submitted, it is not completing.

  What should be done to identify the issue?

  A. Ensure TaskTracker is running

  B. Ensure JobTracker is running

  C. Ensure NameNode is running

  D. Ensure DataNode is running

  Correct Answer: A

• Question 160:

  You have two tables of customers in your database. Customers in cust_table_1 were sent an e-mail promotion last year, and customers in cust_table_2 received a newsletter last year. Customers can only be entered in once per table. You want to create a table that includes all customers, and any of the communications they received last year. Which type of join would you use for this table?

  A. Full outer join

  B. Inner join

  C. Left outer join

  D. Cross join

  Correct Answer: A