EMC EMC Certifications E20-007 Questions & Answers

• Question 111:

  When creating a presentation for a technical audience, what is the main objective?

  A. Show that you met the project goals

  B. Show how you met the project goals

  C. Show if the model will meet the SLA

  D. Show the technique to be used in the production environment

  Correct Answer: B

• Question 112:

  Which word or phrase completes the statement? A Data Scientist would consider that a RDBMS is to a Table as R is to a ______________ .

  A. Data frame

  B. List

  C. Matrix

  D. Array

  Correct Answer: A

• Question 113:

  Which word or phrase completes the statement? Structured data is to OLAP data as quasi- structured data is to____

  A. Clickstream data

  B. XML data

  C. Text documents

  D. Image files

  Correct Answer: A

• Question 114:

  The average purchase size from your online sales site is $17, 200. The customer experience team believes a certain adjustment of the website will increase sales. A pilot study on a few hundred customers showed an increase in average purchase size of $1.47, with a significance level of p=0.1.

  The team runs a larger study, of a few thousand customers. The second study shows an increased average purchase size of $0.74, with a significance level of 0.03. What is your assessment of this study?

  A. The change in purchase size is not practically important, and the good p-value of the second study is probably a result of the large study size.

  B. The change in purchase size is small, but may aggregate up to a large increase in profits over the entire customer base.

  C. The difference in the change in purchase size between the two studies is troubling; The team should run another, larger study.

  D. The p-value of the second study shows a statistically significant change in purchase size. The new website is an improvement.

  Correct Answer: A

• Question 115:

  You are given 10, 000, 000 user profile pages of an online dating site in XML files, and they are stored in HDFS. You are assigned to divide the users into groups based on the content of their profiles. You have been instructed to try K-means clustering on this data. How should you proceed?

  A. Run MapReduce to transform the data, and find relevant key value pairs.

  B. Divide the data into sets of 1, 000 user profiles, and run K-means clustering in RHadoop iteratively.

  C. Run a Naive Bayes classification as a pre-processing step in HDFS.

  D. Partition the data by XML file size, and run K-means clustering in each partition.

  Correct Answer: A

• Question 116:

  Your customer provided you with 2, 000 unlabeled records and asked you to separate them into three groups. What is the correct analytical method to use?

  A. K-means clustering

  B. Linear regression

  C. Naive Bayesian classification

  D. Logistic regression

  Correct Answer: A

• Question 117:

  What does the R code

  z <- f[1:10, ]

  do?

  A. Assigns the first 10 rows of f to the vector z

  B. Assigns the 1st 10 columns of the 1st row of f to z

  C. Assigns a sequence of values from 1 to 10 to z

  D. Assigns the 1st 10 columns to z

  Correct Answer: A

• Question 118:

  You are attempting to find the Euclidean distance between two centroids:

  Centroid A's coordinates: (X = 2, Y = 4)

  Centroid B's coordinates (X = 8, Y = 10)

  Which formula finds the correct Euclidean distance?

  A. SQRT((2-8)2+(4-10)2) or 8.49

  B. SQRT(((2-8) x 2) + ((4-10) x 2)) or 12.17

  C. ((2-8)2+(4-10)2) or 72

  D. ((2-8) x 2 + (4-10) x 2) or 148

  Correct Answer: A

• Question 119:

  In which phase of the data analytics lifecycle do Data Scientists spend the most time in a project?

  A. Discovery

  B. Data Preparation

  C. Model Building

  D. Communicate Results

  Correct Answer: B

• Question 120:

  What is a property of windows functions in SQL commands?

  A. Used to calculate moving averages over various intervals

  B. Group rows into a single output row

  C. Used between the keywords FROM and WHERE in a SELECT command

  D. Ordering data within a window is not required

  Correct Answer: A