NBT Data Interpretation & Analysis 5

Question 1

The ages of 7 employees are: 25, 32, 28, 45, 32, 38, 41. What is the median age?

Accepted Answer

32

Answer

Sorted order: 25, 28, 32, 32, 38, 41, 45 — the 4th (middle) value is 32.

Question 2

A class of 10 students has scores: 70, 75, 80, 80, 85, 90, 90, 90, 95, 100. What is the mode of these scores?

Accepted Answer

90

Answer

90 appears 3 times, more than any other value, so it is the mode.

Question 3

A sample of 6 values has a mean of 15. Five of the values are 12, 18, 10, 20, and 16. What is the sixth value?

Accepted Answer

14

Answer

Required sum = 15 × 6 = 90; sum of five known values = 76; sixth value = 90 − 76 = 14.

Question 4

A bag contains 5 red marbles, 3 blue marbles, and 2 green marbles. If one marble is drawn at random, what is the probability of drawing a blue marble?

Accepted Answer

0.30

Answer

P(blue) = 3 / (5 + 3 + 2) = 3 / 10 = 0.30.

Question 5

A data set contains the values: 12, 15, 18, 22, 22, 25, 30. What is the interquartile range (IQR)?

Accepted Answer

10

Answer

Q1 = 15 and Q3 = 25; IQR = Q3 − Q1 = 25 − 15 = 10.

(NBT) National Benchmark Test Practice Test

(NBT) National Benchmark Test Practice Test

NBT Data Interpretation & Analysis 5