FAST Descriptive Statistics 3

Question 1

A dataset's mean is 50 and standard deviation is 10. A value of 70 has a z-score of:

Accepted Answer

2

Answer

Z = (value − mean) / SD = (70 − 50) / 10 = 20 / 10 = 2.

Question 2

The heights (cm) of 5 students are: 160, 165, 170, 175, 180. What is the mean absolute deviation (MAD)?

Accepted Answer

6

Answer

Mean = 170; absolute deviations: 10, 5, 0, 5, 10; MAD = 30/5 = 6.

Question 3

In a dataset, the 90th percentile value means:

Accepted Answer

90% of values fall at or below it

Answer

The nth percentile is the value below which n% of the data falls.

Question 4

Which of the following best describes a leptokurtic distribution compared to a normal distribution?

Accepted Answer

Taller peak with heavier tails

Answer

Leptokurtic distributions have positive excess kurtosis, meaning a sharper peak and heavier tails than a normal distribution.

Question 5

Data: 3, 7, 7, 2, 9, 3, 7. What is the mode?

Accepted Answer

7

Answer

7 appears three times, which is more than any other value, making it the mode.

(FAST) Future Aptitude Selection Tool Practice Test