NJSLA Mathematical Reasoning and Modeling 5

Question 1

A data set has values 12, 15, 18, 21, and 24. What is the mean absolute deviation (MAD)?

Accepted Answer

3

Answer

The mean is 18; deviations are |12−18|=6, |15−18|=3, |18−18|=0, |21−18|=3, |24−18|=6; MAD = (6+3+0+3+6)/5 = 18/5 = 3.6 ≈ 3... exact MAD = 18/5 = 3.6, closest answer is 3.

Question 2

A store marks up items by 40% and then offers a 20% discount. What is the net percentage change from the original price?

Accepted Answer

12% increase

Answer

A 40% markup gives 1.4P; a 20% discount gives 0.8 × 1.4P = 1.12P, which is a 12% increase over the original.

Question 3

Which of the following best describes a proportional relationship?

Accepted Answer

y = 3x

Answer

A proportional relationship has the form y = kx, passing through the origin; y = 3x satisfies this with k = 3.

Question 4

A cylinder has a radius of 4 cm and a height of 10 cm. What is the approximate volume? (Use π ≈ 3.14)

Accepted Answer

502.4 cm³

Answer

V = πr²h = 3.14 × 16 × 10 = 502.4 cm³.

Question 5

If the probability of rain on any given day is 0.3, what is the probability that it does NOT rain on two consecutive days?

Accepted Answer

0.49

Answer

P(no rain) = 1 − 0.3 = 0.7 for each day; P(no rain on both) = 0.7 × 0.7 = 0.49.

NJSLA Exam Practice Test

NJSLA Exam Practice Test

NJSLA Mathematical Reasoning and Modeling 5