EMC E20-026 Online Practice Questions and Exam Preparation

EMC E20-026 Online Questions & Answers

• Question 101:

  You are analyzing a time series and want to determine its stationarity. You also want to determine the order of autoregressive models. How are the autocorrelation functions used?

  A. ACF as an indication of stationarity,and PACF for the correlation between Xt and Xt-k not explained by their mutual correlation with X1 through Xk-1.
  B. PACF as an indication of stationarity,and ACF for the correlation between Xt and Xt-k not explained by their mutual correlation with X1 through Xk-1.
  C. ACF as an indication of stationarity,and PACF to determine the correlation of X1 through Xk-1.
  D. PACF as an indication of stationarity,and ACF to determine the correlation of X1 through Xk-1.
  A. ACF as an indication of stationarity,and PACF for the correlation between Xt and Xt-k not explained by their mutual correlation with X1 through Xk-1.

• Question 102:

  Which word or phrase completes the statement?

  Theater actor is to "Artistic and Expressive" as Data Scientist is to ________________

  A. "Communicative and Collaborative"
  B. "Introverted and Technical"
  C. "Logical and Steadfast"
  D. "Independent and Intelligent"
  A. "Communicative and Collaborative"

• Question 103:

  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
  C. A binary value

• Question 104:

  Refer to the exhibit.

  You have run a linear regression model against your data, and have plotted true outcome versus predicted outcome. The R-squared of your model is 0.75. What is your assessment of the model?

  

  A. The R-squared may be biased upwards by the extreme-valued outcomes. Remove them and refit to get a better idea of the model's quality over typical data.
  B. The R-squared is good. The model should perform well.
  C. The extreme-valued outliers may negatively affect the model's performance. Remove them to see if the R-squared improves over typical data.
  D. The observations seem to come from two different populations,but this model fits them both equally well.
  A. The R-squared may be biased upwards by the extreme-valued outcomes. Remove them and refit to get a better idea of the model's quality over typical data.

• Question 105:

  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%
  A. 75%

• Question 106:

  In linear regression, what indicates that an estimated coefficient is significantly different than zero?

  A. A small p-value
  B. R-squared near 1
  C. R-squared near 0
  D. The estimated coefficient is greater than 3
  A. A small p-value

• Question 107:

  Refer to the exhibit.

  You are asked to write a report on how specific variables impact your client's sales using a data set provided to you by the client. The data includes 15 variables that the client views as directly related to sales, and you are restricted to these

  variables only.

  After a preliminary analysis of the data, the following findings were made:

  1.

  Multicollinearity is not an issue among the variables

  2.

  Only three variables--A, B, and C--have significant correlation with sales You build a linear regression model on the dependent variable of sales with the independent variables of A, B, and C. The results of the regression are seen in the

  exhibit.

  Which interpretation is supported by the analysis?

  

  A. Variables A,B,and C are significantly impacting sales,but are not effectively estimating sales
  B. Variables A,B,and C are significantly impacting sales and are effectively estimating sales
  C. Due to the R2 of 0.10,the model is not valid ?the linear regression should be re-run with all 15 variables forced into the model to increase the R2
  D. Due to the R2 of 0.10,the model is not valid ?a different analytical model should be attempted
  A. Variables A,B,and C are significantly impacting sales,but are not effectively estimating sales

• Question 108:

  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
  B. Operational process changes

• Question 109:

  Refer to the exhibit.

  The graph represents an ROC space with four classifiers labelled A through D. Which point in the graph represents a perfect classification?

  

  A. S
  B. P
  C. Q
  D. R
  A. S

• Question 110:

  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
  A. Key-value pairs