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Dell EMC Data Science and BigData Certification Questions and Answers



Question : In which of the following cases you can use the K-means clustering?
A. Image Processing
B. Customer Segmentation
C. Classification of the plants
D. Reducing the customer churn rate

: In which of the following cases you can use the K-means clustering?
1. A,B
2. B,C
3. A,B,C
4. B,C,D
5. A,B,C,D

Correct Answer : 5
Explanation: You can use K-Means clustering for various use cases like as below
1. In a video file you can find which all frames are most similar to each other. Attributes can be pixel brightness, color, and its location in the frame.
2. You can use the Patients attributes like sex, age, weight, height, Cholesterol, Sugar etc. to create the groups of the patients. Even you can use clustering in biology for the classification of plants and animals.
3. You can apply k-means clustering on the customers who have the similar spending patterns, and use them to increase the sales or reduce the customer churn rate.





Question : You want to apply the K-Means clustering on the total number of objects which are M, total attributes on each object are n. You need to create groups or clusters. What would be matrix dimension you
would be using to store all the objects attributes?


: You want to apply the K-Means clustering on the total number of objects which are M, total attributes on each object are n. You need to create groups or clusters. What would be matrix dimension you
1. MXn

2. MX5

3. nX5

4. 5X5

5. MXM


Correct Answer : 1
Explanation: As there are M objects then you can have in total M number of rows and there are n attributes then you can have n number of columns to store each object attributes. Hence, correct answer will
be MXn . Number of cluster is given to create the confusion and test your knowledge.




Question : You have data of , people who make the purchasing from a specific grocery store. You also have their income detail in the data. You have created clusters using this data. But in one of the cluster
you see that only 30 people are falling as below
30, 2400, 2600, 2700, 2270 etc.
What would you do in this case?


: You have data of , people who make the purchasing from a specific grocery store. You also have their income detail in the data. You have created clusters using this data. But in one of the cluster
1. You will be increasing number of clusters.

2. You will be decreasing the number of clusters.

3. You will remove that 30 people from dataset

4. You will be multiplying standard deviation with the 100.


Correct Answer : 2
Explanation: Decreasing the number of clusters will help in adjusting this outlier cluster to get adjusted in another cluster.


Related Questions

Question : Which functionality do regular expressions provide?

 : Which functionality do regular expressions provide?
1. increased numerical precision
2. underflow prevention
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4. decreased processing complexity


Question : When creating a project sponsor presentation, what is the main objective?
 : When creating a project sponsor presentation, what is the main objective?
1. Show that you met the project goals
2. Show how you met the project goals
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4. Clearly describe the methods and techniques used


Question : The average purchase size from your online sales site is $, . 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?


 : The average purchase size from your online sales site is $, . The customer experience team
1. 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.
2. The change in purchase size is small, but may aggregate up to a large increase in profits over
the entire customer base.
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should run another, larger study.
4. The p-value of the second study shows a statistically significant change in purchase size. The
new website is an improvement.




Question : Which word or phrase completes the statement? Business Intelligence is to monitoring trends as
Data Science is to ________ trends.
 : Which word or phrase completes the statement? Business Intelligence is to monitoring trends as
1. Predicting
2. Discarding
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4. Optimizing


Question : Consider a scale that has five () values that range from "not important" to "very important". Which
data classification best describes this data?
 : Consider a scale that has five () values that range from
1. Nominal
2. Real
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4. Ordinal



Question : Which key role for a successful analytic project can provide business domain expertise with a
deep understanding of the data and key performance indicators?
 : Which key role for a successful analytic project can provide business domain expertise with a
1. Business User
2. Project Sponsor
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4. Business Intelligence Analyst
5. None of above