PERT Data Interpretation & Statistics 3 — Questions and Answers
Question 1: The mean of 5 numbers is 12. What is their sum?
- 60 (Correct answer)
- 12
- 17
- 50
Correct answer: 60
Sum equals mean times count, so 12 × 5 = 60.
Question 2: If a value is added that equals the current mean, the mean will do what?
- Stay the same (Correct answer)
- Increase
- Decrease
- Double
Correct answer: Stay the same
Adding a value equal to the mean does not change the average.
Question 3: In a frequency table, a class has frequency 8 out of 40 total. What is its relative frequency?
- 0.20 (Correct answer)
- 0.08
- 0.40
- 0.50
Correct answer: 0.20
8 divided by 40 equals 0.20.
Question 4: Which graph type best shows parts of a single whole?
- Pie chart (Correct answer)
- Line graph
- Scatter plot
- Histogram
Correct answer: Pie chart
A pie chart divides one whole into proportional slices.
Question 5: The mean of 4, 6, 8, and x is 7. What is x?
- 10 (Correct answer)
- 7
- 9
- 8
Correct answer: 10
The four values must sum to 28, so x = 28 − 18 = 10.
Question 6: A scatter plot showing points trending downward suggests what correlation?
- Negative (Correct answer)
- Positive
- Zero
- Perfect
Correct answer: Negative
Points falling as x increases indicate a negative correlation.
Question 7: What is the median of 3, 9, 1, 7, 5, 11?
- 6 (Correct answer)
- 5
- 7
- 8
Correct answer: 6
Ordered, the middle two values 5 and 7 average to 6.
PERT Data Interpretation & Statistics 3
The mean of 5 numbers is 12.
What is their sum?