Statistics Descriptive Statistics & Data Summarization 1 — Questions and Answers
Question 1: Which measure of central tendency is most affected by extreme outliers in a dataset?
- Mean (Correct answer)
- Median
- Mode
- Midrange
Correct answer: Mean
The mean is most affected by outliers because it incorporates every value in its calculation.
Question 2: What does the interquartile range (IQR) measure?
- The range of the middle 50% of data (Correct answer)
- The distance between the mean and median
- The total spread of all data
- The variance of the dataset
Correct answer: The range of the middle 50% of data
The IQR is Q3 minus Q1, capturing the spread of the central 50% of the data.
Question 3: A dataset has values: 2, 4, 4, 6, 8. What is the median?
- 4 (Correct answer)
- 4.8
- 5
- 6
Correct answer: 4
With 5 values sorted in order, the median is the 3rd value, which is 4.
Question 4: Which graphical display is best suited for showing the distribution of a single quantitative variable?
- Histogram (Correct answer)
- Bar chart
- Pie chart
- Scatter plot
Correct answer: Histogram
A histogram displays the frequency distribution of a continuous quantitative variable using bins.
Question 5: What is the variance of the dataset {2, 4, 4, 4, 5, 5, 7, 9}?
- 4 (Correct answer)
- 2
- 16
- 3
Correct answer: 4
The mean is 5 and the average squared deviation from the mean equals 4.
Question 6: A positively skewed distribution has its tail extending toward which direction?
- Right (Correct answer)
- Left
- Both directions equally
- Neither direction
Correct answer: Right
A positively skewed (right-skewed) distribution has a long tail on the right side.
Statistics Descriptive Statistics & Data Summarization 1
Which measure of central tendency is most affected by extreme outliers in a dataset?