QUIZZES TEST BANK HARVARD UNIVERSITY
2026/2027 SOLUTION.
Topic: Interpreting Histograms & Skewness
1. A financial analyst creates a histogram of household incomes in a specific metropolitan
area. The distribution has a long tail extending to the right, and the peak is on the left side.
Which of the following statements accurately describes this distribution?
A. The distribution is left-skewed, and the mean is less than the median.
B. The distribution is right-skewed, and the mean is greater than the median.
C. The distribution is symmetric, and the mean equals the median.
D. The distribution is uniform, and there is no mode.
[CORRECT] B
Rationale: In a right-skewed distribution (positive skew), the tail points toward the higher
values (right). The extreme high values pull the mean in the direction of the tail, causing the
mean to be greater than the median.
2. An HBS student analyzes a dataset of final exam scores for a difficult statistics course. The
histogram shows a peak at the high end of the scale (90-100) with a tail extending to the left
toward lower scores. What is the relationship between the mean and median in this
scenario?
A. The mean is greater than the median.
B. The mean is equal to the median.
C. The mean is less than the median.
D. The median is undefined for left-skewed data.
[CORRECT] C
Rationale: This describes a left-skewed distribution (negative skew). The tail on the left pulls
the mean downward, making it less than the median.
,3. (Select All That Apply) A real estate firm plots a histogram of housing prices in a suburb.
The distribution is unimodal and right-skewed. Which of the following statements are true
regarding measures of central tendency?
A. The median represents the 50th percentile of home prices.
B. The mean is the appropriate measure of the "typical" home price because it is resistant to
outliers.
C. The mean is higher than the median due to the influence of expensive outlier properties.
D. The mode is located at the highest frequency bar on the far right of the distribution.
[CORRECT] A, C
Rationale: The median always represents the 50th percentile (A). In a right-skewed
distribution, high-value outliers pull the mean upward, making it higher than the median (C).
The mean is not resistant to outliers (B is false). The mode is located at the peak, which is on
the left for a right-skewed distribution (D is false).
4. (Calculation) A dataset of factory defect rates has a mean of 3.2% and a median of 2.8%.
Based solely on these metrics, what can be inferred about the shape of the distribution?
A. It is left-skewed.
B. It is right-skewed.
C. It is perfectly symmetric.
D. It is bimodal.
[CORRECT] B
Rationale: When the mean (3.2%) is greater than the median (2.8%), the distribution is
positively (right) skewed. The mean is pulled in the direction of the skew (towards the tail).
5. (True/False) In a left-skewed distribution of customer satisfaction ratings (scale 1-10), the
"tail" of the distribution represents the customers who provided the lowest ratings.
A. True
B. False
[CORRECT] B
,Rationale: This is a common visualization error. In a left-skewed distribution, the tail extends
to the left (towards lower values), but the bulk of the data is concentrated on the right (high
values). The tail actually represents the few customers with low ratings, but the "skew" is
named after the tail's direction. The statement implies the tail represents the majority, which
is incorrect; the tail represents the outliers.
Topic: Standard Deviation & Coefficient of Variation
6. An investor is comparing two stocks: Stock A has an average return of 10% with a standard
deviation of 5%. Stock B has an average return of 20% with a standard deviation of 10%.
Which stock has the higher relative risk as measured by the Coefficient of Variation (CV)?
A. Stock A (CV = 50%)
B. Stock B (CV = 50%)
C. Stock A (CV = 200%)
D. Stock B (CV = 200%)
[CORRECT] A
Rationale: The Coefficient of Variation is calculated as (Standard Deviation / Mean) * 100. For
Stock A: (5/10)*100 = 50%. For Stock B: (10/20)*100 = 50%. While the risk is statistically
identical in relative terms, if the question implies a strict comparison of volatility relative to
size, they are equal. Correction: Let's adjust the prompt for a clear distinction.
Revised Question 6: Stock A has a mean of 10% and SD of 5%. Stock B has a mean of 50% and
SD of 10%. Which has higher relative risk?
Revised Answer: Stock A CV = 50%. Stock B CV = 20%. Stock A has higher relative risk.
(Note: In the generated output below, I will use the distinct version for clarity).
7. Why is the Coefficient of Variation (CV) preferred over raw Standard Deviation when
comparing the volatility of a stock price (e.g., $150) versus the volatility of Earnings Per Share
(e.g., $1.50)?
A. Standard Deviation is sensitive to outliers, while CV is not.
B. Standard Deviation is an absolute measure and does not account for the scale of the
variables, whereas CV measures relative variability.
, C. CV can only be used for normally distributed data.
D. Standard Deviation cannot be calculated for financial data.
[CORRECT] B
Rationale: The standard deviation is in the units of the data (dollars). Comparing a $5
standard deviation on a $150 stock vs a $0.50 SD on a $1.50 EPS is misleading without scaling.
CV standardizes the risk by dividing by the mean, allowing for direct comparison across
different units or scales.
8. (Select All That Apply) A portfolio manager calculates the standard deviation of monthly
returns for a bond fund as 2% and a tech stock fund as 15%. What does this imply about the
data?
A. The tech stock fund has higher absolute volatility.
B. The tech stock fund has higher relative risk (assuming the means are similar).
C. The bond fund has a tighter distribution of returns around the mean.
D. The bond fund is a better investment.
[CORRECT] A, C
Rationale: Standard deviation measures absolute volatility (A). A smaller standard deviation
indicates data points are closer to the mean (C). We cannot determine relative risk (B)
without knowing the mean returns (CV calculation). We cannot determine investment quality
(D) solely based on volatility.
9. (Calculation) A company’s earnings per share (EPS) has a mean of $2.00 and a standard
deviation of $0.40. The stock price has a mean of $50.00 and a standard deviation of $10.00.
Calculate the Coefficient of Variation for both to determine which dataset varies more relative
to its mean.
A. EPS has a higher CV (20%) than Stock Price (20%).
B. Stock Price has a higher CV (20%) than EPS (20%).
C. Both have the same CV (20%), indicating identical relative variability.
D. Cannot be determined without the sample size.