CSET Data Analysis & Reporting 3 — Questions and Answers
Question 1: A dataset has values: 4, 7, 7, 9, 12, 15, 21. What is the interquartile range (IQR)?
- 7
- 8 (Correct answer)
- 9
- 17
Correct answer: 8
Q1 = 7 and Q3 = 15, so IQR = 15 - 7 = 8, representing the spread of the middle 50% of data.
Question 2: Which type of data display would best show how a single student's monthly quiz scores changed over an entire school year?
- Histogram
- Box plot
- Line graph (Correct answer)
- Stem-and-leaf plot
Correct answer: Line graph
A line graph is ideal for showing trends and changes in a variable over continuous time periods.
Question 3: A teacher administers the same standardized test to 30 students and gets highly consistent results each time. This test is said to have high:
- Validity
- Reliability (Correct answer)
- Bias
- Standardization
Correct answer: Reliability
Reliability refers to the consistency of a test in producing the same results across repeated administrations.
Question 4: In a frequency table, the relative frequency column shows values that should sum to approximately:
- The total number of observations
- 100 or 1.0 (Correct answer)
- The mean of the data
- 0
Correct answer: 100 or 1.0
Relative frequencies represent proportions or percentages of the total, so they sum to 1.0 (or 100%).
Question 5: A student scores at the 75th percentile on a standardized test. This means:
- The student answered 75% of questions correctly
- The student scored higher than 75% of the norm group (Correct answer)
- The student's score is in the top 25% of all possible scores
- The student is performing above average by 75 points
Correct answer: The student scored higher than 75% of the norm group
A percentile rank of 75 means the student performed as well as or better than 75% of the students in the comparison group.
Question 6: Which of the following best describes a positively skewed distribution?
- The mean equals the median
- The tail extends to the left
- The tail extends to the right (Correct answer)
- The data is evenly distributed
Correct answer: The tail extends to the right
A positively skewed distribution has a longer tail on the right side, pulling the mean above the median.
Question 7: When calculating standard deviation, a larger value indicates:
- Data points are clustered close to the mean
- The mean is very high
- Data points are more spread out from the mean (Correct answer)
- There are more data points in the set
Correct answer: Data points are more spread out from the mean
Standard deviation measures dispersion; a larger value means data points deviate more from the mean on average.
CSET Data Analysis & Reporting 3
A dataset has values: 4, 7, 7, 9, 12, 15, 21.
What is the interquartile range (IQR)?