NCDAP Data Analysis & Statistics 1 — Questions and Answers
Question 1: A student scored 72, 85, 90, 68, and 95 on five tests. What is the mean (average) score?
- 82 (Correct answer)
- 85
- 80
- 90
Correct answer: 82
The mean is calculated by adding all scores (72+85+90+68+95=410) and dividing by the count (410÷5=82).
Question 2: What is the median of the following data set: 3, 7, 1, 9, 4, 6, 2?
- 4 (Correct answer)
- 3
- 6
- 5
Correct answer: 4
After ordering the values (1, 2, 3, 4, 6, 7, 9), the median is the middle value, which is 4.
Question 3: In a data set of 8 values, what is the position of the median?
- Between the 4th and 5th values (Correct answer)
- The 4th value
- The 5th value
- Between the 3rd and 4th values
Correct answer: Between the 4th and 5th values
When a data set has an even number of values, the median is the average of the two middle values — here the 4th and 5th.
Question 4: The mode of the data set 5, 8, 3, 5, 9, 2, 5, 8 is:
- 5 (Correct answer)
- 8
- 3
- No mode
Correct answer: 5
The mode is the value that appears most often; 5 appears three times, more than any other value.
Question 5: A bar graph shows monthly rainfall. January had 3 inches, February had 5 inches, and March had 4 inches. What was the total rainfall for these three months?
- 12 inches (Correct answer)
- 10 inches
- 15 inches
- 9 inches
Correct answer: 12 inches
Adding the three months: 3 + 5 + 4 = 12 inches total rainfall.
Question 6: What does the range of a data set measure?
- The spread between the highest and lowest values (Correct answer)
- The most frequently occurring value
- The middle value when data is ordered
- The sum of all values divided by the count
Correct answer: The spread between the highest and lowest values
Range = maximum value − minimum value, so it measures how spread out the data is.
Question 7: A pie chart shows that 40% of students prefer math, 35% prefer English, and the rest prefer science. What percentage prefers science?
- 25% (Correct answer)
- 30%
- 20%
- 15%
Correct answer: 25%
All percentages must sum to 100%, so science = 100% − 40% − 35% = 25%.
NCDAP Data Analysis & Statistics 1
A student scored 72, 85, 90, 68, and 95 on five tests.
What is the mean (average) score?