EMC E20-026 Online Practice Questions and Exam Preparation

EMC E20-026 Online Questions & Answers

• Question 141:

  Refer to the exhibit.

  In the exhibit, a correlogram is provided based on an autocorrelation analysis of a sample dataset.

  What can you conclude from only this exhibit?

  

  A. There is significant autocorrelation through lag 3
  B. There is no structure left to model in the data
  C. Lag 7 has a significant negative autocorrelation
  D. Differencing is required before proceeding with any analysis
  A. There is significant autocorrelation through lag 3

• Question 142:

  Refer to the exhibit.

  Click on the calculator icon in the upper left corner. You are going into a meeting where you know your manager will have a question on your dataset -- specifically relating to customers that are classified as renters with good credit status.

  In order to prepare for the meeting, you create a rule: RENTER => GOOD CREDIT. What is the confidence of the rule?

  

  A. 63%
  B. 41%
  C. 18%
  D. 73%
  A. 63%

• Question 143:

  Which word or phrase completes the statement? Data-ink ratio is to data visualization as __________ .

  A. Confusion matrix is to classifier
  B. Data scientist is to big data
  C. Seasonality is to ARIMA
  D. K-means is to Naive Bayes
  A. Confusion matrix is to classifier

• Question 144:

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

• Question 145:

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

• Question 146:

  Which word or phrase completes the statement? Mahout is to Hadoop as MADlib is to ____________ .

  A. PostgreSQL
  B. R
  C. Excel
  D. SAS
  A. PostgreSQL

• Question 147:

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

  A. Stemming
  B. Parsing
  C. Digitizing
  D. Sorting
  A. Stemming

• Question 148:

  Refer to the exhibit.

  You are using k-means clustering to discover groupings within a data set. You plot within-sum-of-squares (wss) of multiple cluster sizes. Based on the exhibit, how many clusters should you use in your analysis?

  

  A. 4
  B. 2
  C. 8
  D. 10
  A. 4

• Question 149:

  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
  A. Mahout

• Question 150:

  You have fit a decision tree classifier using 12 input variables. The resulting tree used 7 of the 12 variables, and is 5 levels deep. Some of the nodes contain only 3 data points. The AUC of the model is 0.85. What is your evaluation of this model?

  A. The tree is probably overfit. Try fitting shallower trees and using an ensemble method.
  B. The AUC is high,and the small nodes are all very pure. This is an accurate model.
  C. The tree did not split on all the input variables. You need a larger data set to get a more accurate model.
  D. The AUC is high,so the overall model is accurate. It is not well-calibrated,because the small nodes will give poor estimates of probability.
  A. The tree is probably overfit. Try fitting shallower trees and using an ensemble method.