Core Academic Skills Assessment Mathematics: Data and Statistics 5

Question 1

A line of best fit for a data set is y = 3x + 2. If x = 7, what does the model predict for y?

Accepted Answer

23

Answer

y = 3(7) + 2 = 21 + 2 = 23.

Question 2

Which measure best describes the spread of a dataset that contains significant outliers?

Accepted Answer

IQR

Answer

The IQR is based on the middle 50% of data and is resistant to the influence of outliers.

Question 3

A class of 30 students took a test. The mean score was 72. If 5 more students scored 90 each, what is the new mean?

Accepted Answer

75.14

Answer

Original sum = 30 × 72 = 2160; new sum = 2160 + 5 × 90 = 2610; new mean = 2610 / 35 ≈ 74.57.

Question 4

A cumulative frequency graph (ogive) shows that 60% of students scored below 75. If there are 200 students, how many scored 75 or above?

Accepted Answer

80

Answer

60% scored below 75, so 40% scored 75 or above; 0.40 × 200 = 80 students.

Question 5

A coin is flipped 3 times. What is the probability of getting exactly 2 heads?

Accepted Answer

3/8

Answer

The combinations for exactly 2 heads (HHT, HTH, THH) = 3 out of 8 equally likely outcomes, so P = 3/8.

Core Academic Skills Assessment Practice Test