Objective 3.1 Examine Data CERTIFIED-DATA-SCIENCE-PRACTITIONER Practice Questions (Page 5)

Questions 21–25

1. 21foundation · easy

   Which correlation coefficient is appropriate for measuring the monotonic relationship between two ordinal variables?

   • AZ-score
   • BPearson
   • CVariance
   • DSpearman
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2. 22foundation · easy

   What does the standard deviation of a numerical feature describe?

   • AThe most common value in the data
   • BThe spread of values around the mean
   • CThe midpoint between the minimum and maximum values
   • DThe shape of the distribution
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4. 23expert · medium

   A data scientist is analyzing 'transaction_amount' data. The mean is $120, the median is $45, and the standard deviation is $300. A box plot shows many points beyond the upper whisker. The client insists on reporting a single 'typical' value. Which measure should the data scientist report and why?

   • AReport the median ($45) because it is robust to the extreme outliers that inflate the mean.
   • BReport the mode because it is the most frequent value.
   • CReport the standard deviation ($300) because it shows the spread.
   • DReport the mean ($120) because it uses all the data points.
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5. 24foundation · easy

   Which of the following is an example of a numerical feature?

   • AProduct category
   • BZip code
   • CAge in years
   • DCustomer ID
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6. 25foundation · easy

   What does a heatmap commonly display in the context of multivariate analysis?

   • AThe frequency of categories in a bar chart
   • BThe relationship between two categorical variables only
   • CThe values of a matrix, such as correlations between multiple variables
   • DThe distribution of a single variable
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