Describe and Provide Examples of the Most Important Statistical Measures and Effective Visualizations of Data DATA-SCIENCE-FOUNDATIONS Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   Given the dataset [4, 8, 6, 5, 3], what is the standard deviation? (Round to one decimal place.)

   • A1.9
   • B1.4
   • C3.7
   • D2.0
   Reveal Solution Discussion Select an answer first
2. 17expert · hard

   A data scientist is analyzing the distribution of response times for a web application. The data is heavily right-skewed, with most responses taking under 1 second, but occasional responses taking over 10 seconds. The scientist needs to report a 'typical' response time and a measure of variability that is not unduly influenced by these slow outliers. Which pair of statistics is most appropriate?

   • AMedian and standard deviation
   • BMode and range
   • CMean and standard deviation
   • DMedian and interquartile range (IQR)
   Reveal Solution Discussion Select an answer first
4. 18application · easy

   A non-profit organization wants to visualize the percentage of total donations received from each of its 5 major funding sources (e.g., individuals, corporations, foundations, government grants, events). The goal is to show the relative proportion of each source at a glance. Which visualization is most appropriate?

   • AA box plot
   • BA pie chart
   • CA histogram
   • DA scatter plot
   Reveal Solution Discussion Select an answer first
5. 19expert · medium

   A data analyst is comparing the salaries of employees in two departments. Department A has a mean salary of $70,000 and a standard deviation of $5,000. Department B has a mean salary of $70,000 and a standard deviation of $20,000. Both distributions are symmetric. What is the most important conclusion from this comparison?

   • ADepartment B has a higher median salary than Department A.
   • BDepartment B has more variability in salaries, meaning salaries are more spread out around the mean compared to Department A.
   • CThe salaries in Department B are more likely to be negatively skewed.
   • DDepartment A has more employees than Department B.
   Reveal Solution Discussion Select an answer first
6. 20expert · hard

   A financial analyst is modeling the returns of a new investment fund. The analyst calculates that the distribution of daily returns has high kurtosis (leptokurtic). The mean return is 0.1% and the standard deviation is 1%. What is the most important implication of the high kurtosis for risk assessment?

   • AThe distribution is skewed to the right, so the mean is higher than the median.
   • BThe distribution has heavier tails than a normal distribution, meaning extreme returns (both positive and negative) are more likely than the standard deviation alone suggests.
   • CThe mean return is not a reliable measure of central tendency because of the high kurtosis.
   • DThe standard deviation is underestimated and should be recalculated using the interquartile range.
   Reveal Solution Discussion Select an answer first