ALEKS Statistics and Probability 1 — Questions and Answers
Question 1: What is the mean of the data set: 4, 7, 10, 13, 16?
- 10 (Correct answer)
- 7
- 13
- 9
Correct answer: 10
Mean = (4 + 7 + 10 + 13 + 16) ÷ 5 = 50 ÷ 5 = 10.
Question 2: What is the median of: 3, 7, 9, 12, 15, 18?
- 10.5 (Correct answer)
- 9
- 12
- 10
Correct answer: 10.5
With 6 values, the median is the average of the 3rd and 4th: (9 + 12)/2 = 10.5.
Question 3: A bag has 3 red, 5 blue, and 2 green marbles. What is the probability of picking a blue marble?
- 1/2 (Correct answer)
- 5/3
- 1/5
- 3/10
Correct answer: 1/2
P(blue) = 5/10 = 1/2.
Question 4: What is the mode of: 2, 4, 4, 6, 7, 9, 9, 9?
- 9 (Correct answer)
- 4
- 6
- 7
Correct answer: 9
9 appears three times, more than any other value, making it the mode.
Question 5: Two fair coins are tossed. What is the probability of getting exactly one head?
- 1/2 (Correct answer)
- 1/4
- 3/4
- 2/3
Correct answer: 1/2
Outcomes with exactly one head: HT, TH — that's 2 out of 4 total outcomes = 1/2.
Question 6: What measure of central tendency is most affected by outliers?
- Mean (Correct answer)
- Median
- Mode
- Range
Correct answer: Mean
The mean uses every value in its calculation, so extreme outliers pull it significantly up or down.
ALEKS Statistics and Probability 1
What is the mean of the data set: 4, 7, 10, 13, 16?