Core Academic Skills Assessment Mathematics: Data and Statistics 3

Question 1

A histogram has 5 bars with frequencies 3, 7, 12, 8, 4 from left to right. The distribution is best described as:

Accepted Answer

Approximately symmetric

Answer

The frequencies rise to a peak in the middle and fall off symmetrically, indicating an approximately bell-shaped, symmetric distribution.

Question 2

The probability of rain on any given day is 0.3. Assuming independence, what is the probability it rains on exactly 0 of the next 2 days?

Accepted Answer

0.49

Answer

P(no rain both days) = 0.7 × 0.7 = 0.49.

Question 3

Which graph type is BEST for showing how a quantity changes over time?

Accepted Answer

Line graph

Answer

Line graphs connect data points across time intervals, making trends and changes over time easy to see.

Question 4

A store records daily sales (in dollars): 120, 145, 130, 160, 125, 140, 150. What is the mean daily sales?

Accepted Answer

141.43

Answer

Sum = 970; mean = 970 ÷ 7 ≈ 138.57. Wait — 120+145+130+160+125+140+150 = 970; 970/7 ≈ 138.57, so the correct answer is 138.57.

Question 5

In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?

Accepted Answer

68%

Answer

The empirical (68-95-99.7) rule states that about 68% of data falls within one standard deviation of the mean.

Core Academic Skills Assessment Practice Test