Free HBS Data Analysis Questions and Answers — Questions and Answers
Question 1: Which of the following is the mean of the numbers 5, 7, 8, 10, and 15?
- 9 (Correct answer)
- 10
- 8
- 11
Correct answer: 9
The mean (or average) of a set of numbers is calculated by summing all the numbers and then dividing by the total count of numbers in the set. For the numbers 5, 7, 8, 10, and 15, the sum is 5 + 7 + 8 + 10 + 15 = 45. Since there are 5 numbers, the mean is 45 / 5 = 9.
Question 2: In a class of 30 students, 18 are girls. What percentage of the class are girls?
- 50%
- 60% (Correct answer)
- 40%
- 70%
Correct answer: 60%
To find the percentage of girls in the class, you divide the number of girls by the total number of students and then multiply by 100. In this case, (18 girls / 30 students) * 100%. This calculation results in (0.6) * 100% = 60%.
Question 3: What is the median of the following set of numbers: 3, 7, 8, 12, 15?
- 7
- 8 (Correct answer)
- 12
- 15
Correct answer: 8
The median is the middle value in a numerically ordered set of numbers. For the set 3, 7, 8, 12, 15, the numbers are already arranged in ascending order. With five numbers, the third number from either end is the middle one. Therefore, 8 is the median of this set.
Question 4: If the mode of a set of numbers is 4, which of the following sets could be the correct data set?
- 1, 2, 3, 4
- 2, 3, 4, 5, 6
- 3, 5, 6, 7
- 4, 4, 5, 6 (Correct answer)
Correct answer: 4, 4, 5, 6
The mode of a set of numbers is the value that appears most frequently. In the data set 4, 4, 5, 6, the number 4 appears twice, which is more often than any other number in the set. Therefore, 4 is the mode for this particular data set.
Question 5: If 25% of a data set is 20, what is the total number in the data set?
- 80
- 50
- 100 (Correct answer)
- 40
Correct answer: 100
To find the total number when a percentage of it is known, you can divide the given value by the percentage (expressed as a decimal). If 20 represents 20% of the total (0.20), then the total would be 20 / 0.20 = 100. This calculation determines the whole amount based on a known part and its corresponding percentage.
Which of the following is the mean of the numbers 5, 7, 8, 10, and 15?