Describe and Provide Examples of the Most Important Statistical Measures and Effective Visualizations of Data DATA-SCIENCE-FOUNDATIONS Practice Questions (Page 2)

Questions 6–10

1. 6application · easy

   A sports analyst wants to show the relationship between a player's age and their performance score. The analyst suspects the relationship might not be perfectly linear. Which visualization should the analyst create first to explore this relationship?

   • AA histogram of performance scores
   • BA box plot of age by performance quartile
   • CA scatter plot of age vs. performance score
   • DA bar chart of average performance by age group
   Reveal Solution Discussion Select an answer first
2. 7application · easy

   A data analyst needs to present the change in quarterly revenue over the last 5 years to company executives. The goal is to highlight the trend and seasonal patterns. Which visualization is most effective?

   • AA histogram of revenue values
   • BA line chart with time on the x-axis and revenue on the y-axis
   • CA box plot of revenue by year
   • DA pie chart of revenue by quarter
   Reveal Solution Discussion Select an answer first
4. 8application · medium

   A data analyst at a retail company is summarizing the monthly sales figures for 12 stores. The dataset contains one extreme outlier: a store that had a temporary promotional surge generating sales 10 times higher than the others. The analyst needs to report a 'typical' monthly sales value that is not distorted by this outlier. Which measure of central tendency should the analyst use, and which visualization would best support the report?

   • AMode and a pie chart of sales proportions
   • BMedian and a box plot of store sales
   • CMean and a bar chart of each store's sales
   • DRange and a line chart of sales over time
   Reveal Solution Discussion Select an answer first
5. 9application · easy

   A city planner needs to present the distribution of commute times for 5,000 residents to a non-technical audience. The goal is to show the overall shape of the distribution, the typical commute, and the spread, while keeping the chart simple to interpret. Which visualization is most effective for this purpose?

   • AA line chart of commute times sorted in ascending order
   • BA pie chart showing the percentage of residents in each 10-minute interval
   • CA stacked bar chart of average commute by age group
   • DA histogram with 20 bins
   Reveal Solution Discussion Select an answer first
6. 10expert · hard

   An analyst is studying the relationship between employee tenure (years) and job satisfaction score (1-10). The Pearson correlation is r = 0.02, suggesting no linear relationship. However, a scatter plot reveals a clear U-shaped pattern: satisfaction is high for new employees, drops in the middle years, and rises again for long-tenured employees. What is the most appropriate conclusion and next step?

   • AThe analyst should calculate the mean satisfaction for each tenure year and report the correlation of those means.
   • BThe analyst should remove the middle-tenure employees as outliers to force a linear relationship.
   • CThe correlation of 0.02 is valid, and the analyst should conclude there is no relationship between tenure and satisfaction.
   • DThe Pearson correlation is misleading because it only measures linear relationships; the analyst should report the non-linear pattern and consider non-linear correlation measures or polynomial regression.
   Reveal Solution Discussion Select an answer first