D-DS-FN-23 by EMC Actual Free Exam Q&As

Question 1

What is a benefit of Spark in-memory data processing as opposed to using MapReduce?

A. Removes the need to use disks at all, which reduces cost B. Supports processing unstructured data, which MapReduce does not allow C. Allows parallel processing, which MapReduce does not support D. Avoids writing intermediate data to disk, which speeds up processing

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Correct Answer: D Vote an answer

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Question 2

Refer to the exhibit.

You have plotted the distribution of savings account sizes for your bank.
How would you proceed, based on this distribution?

A. The accounts of size greater than 2500 are rare, and probably outliers. Eliminate them from your future analysis. B. The data is extremely skewed. Splityour analysis into two cohorts: accountsless than 2500, and accounts greater than 2500 C. The data is extremely skewed. Replot the data on a logarithmic scale to get a better sense of it. D. The data is extremely skewed, but looks bimodal; replot the data in the range 2, 500-10, 000 to be sure.

Discussion 0

Correct Answer: C Vote an answer

Question 3

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 tabluated them as shown in the exhibit.
What are the Precision and Recall rate of the model?

A. Precision = 277/262 Recall = 288/262 B. Precision = 262/277 Recall = 262/288 C. Precision = 288/262 Recall = 277/262 D. Precision =262/288 Recall = 262/277

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Correct Answer: B Vote an answer

Question 4

In the Map Reduce framework, what is the purpose of the Map Function?

A. It processes the input and generates key-value pairs B. It collects the output of the Reduce function C. It breaks the input into smaller components and distributes to other nodes in the cluster D. It sorts the results of the Reduce function

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Correct Answer: A Vote an answer

Question 5

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

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

Discussion 0

Correct Answer: C Vote an answer

Question 6

When would you use a Wilcoxson Rank Sum test?

A. When the populations represent the sums of other values B. When the data can easily be sorted C. When the data cannot easily be sorted D. When you cannot make an assumption about the distribution of the populations

Discussion 0

Correct Answer: D Vote an answer

Question 7

In addition to quantitative and technical skills, what is a key aspect of the profile of a data scientist?

A. Project management and administrative skills B. Proficient in Microsoft Project and Excel C. Accounting and regulatory skills D. Skeptical and critical thinking

Discussion 0

Correct Answer: D Vote an answer

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Question 8

A call center for a large electronics company handles an average of 35, 000 support calls a day. The head of the call center would like to optimize the staffing of the call center during the rollout of a new product due to recent customer complaints of long wait times.
You have been asked to create a model to optimize call center costs and customer wait times.
The goals for this project include:
1. Relative to the release of a product, how does the call volume change over time?
2. How to best optimize staffing based on the call volume for the newly released product, relative to old products.
3. Historically, what time of day does the call center need to be most heavily staffed?
4. Determine the frequency of calls by both product type and customer language.
Which goals are suitable to be completed with MapReduce?

A. Goal 1 and 3 B. Goals 1, 2, 3, 4 C. Goal 2 and 4 D. Goals 2, 3, 4

Discussion 0

Correct Answer: C Vote an answer

Question 9

What is one modeling or descriptive statistical function in MADlib that is typically not provided in a standard relational database?

A. Quantiles B. Variance C. Expected value D. Linear regression

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Correct Answer: D Vote an answer

Question 10

You have created a scatterplot of two continuous variables for 2000 records. You want to add a line to the scatterplot to check linearity of the data.
Which function would best address this need?

A. abline() B. lm() C. hist() D. glm()

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Correct Answer: A Vote an answer

Question 11

Which word or phrase completes the statement? A data warehouse is to a centralized database for reporting as an analytic sandbox is to a _______?

A. Centralized database of KPIs B. Collection of data assets for ETL C. Collection of low-volume databases D. Collection of data assets for modeling

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Correct Answer: D Vote an answer

EMC Dell Data Science Foundations - D-DS-FN-23 Exam Practice Test