Rise Placement Test Statistics and Data Analysis 2 — Questions and Answers
Question 1: Which measure of central tendency is most affected by an extreme outlier in a data set?
- Mean (Correct answer)
- Median
- Mode
- Range
Correct answer: Mean
The mean uses every data value in its calculation, so an extreme outlier pulls it significantly higher or lower.
Question 2: A scatter plot shows that as study hours increase, test scores also increase. This relationship is best described as:
- Positive correlation (Correct answer)
- Negative correlation
- No correlation
- Inverse proportion
Correct answer: Positive correlation
When both variables increase together, the data displays a positive correlation.
Question 3: A data set has a mean of 50 and a standard deviation of 5. What does a standard deviation of 5 tell you?
- Most data points are within 5 units of the mean (Correct answer)
- The data has 5 outliers
- The median is 5
- The range is 5
Correct answer: Most data points are within 5 units of the mean
Standard deviation measures the average spread around the mean, so a value of 5 means data typically falls within 5 units of 50.
Question 4: A frequency table shows: Score 60–69 (5 students), 70–79 (8 students), 80–89 (12 students), 90–99 (5 students). What percent scored in the 80–89 range?
- 40% (Correct answer)
- 12%
- 30%
- 50%
Correct answer: 40%
Total students = 5+8+12+5 = 30; 12/30 × 100 = 40%.
Question 5: In a box-and-whisker plot, the box itself represents which portion of the data?
- The middle 50% (Correct answer)
- The top 25%
- The bottom 25%
- The full range
Correct answer: The middle 50%
The box spans from the first quartile (Q1) to the third quartile (Q3), capturing the interquartile range (middle 50%).
Question 6: A student received grades of 80, 90, and 70 in three classes worth 2, 3, and 1 credit hours respectively. What is the weighted average grade?
- 83.3 (Correct answer)
- 80
- 82
- 85
Correct answer: 83.3
Weighted avg = (80×2 + 90×3 + 70×1) / (2+3+1) = (160+270+70)/6 = 500/6 ≈ 83.3.
Question 7: Two fair coins are flipped. What is the probability of getting exactly one head?
- 1/2 (Correct answer)
- 1/4
- 3/4
- 1/3
Correct answer: 1/2
Possible outcomes: HH, HT, TH, TT — two outcomes (HT, TH) have exactly one head, so probability = 2/4 = 1/2.
Rise Placement Test Statistics and Data Analysis 2
Which measure of central tendency is most affected by an extreme outlier in a data set?