Core Academic Skills Assessment Mathematics: Data and Statistics 4

Question 1

A data set has a mean of 50 and a standard deviation of 5. A value of 60 has a z-score of:

Accepted Answer

2

Answer

z = (60 − 50) / 5 = 10 / 5 = 2.

Question 2

The correlation coefficient between study hours and test scores is r = 0.92. This means:

Accepted Answer

There is a strong positive linear relationship

Answer

A correlation coefficient close to +1 indicates a strong positive linear relationship between the two variables.

Question 3

Which of the following correctly identifies a potential source of bias in a survey?

Accepted Answer

Only surveying people who volunteer

Answer

Voluntary response bias occurs when only those who choose to participate are included, skewing results toward those with strong opinions.

Question 4

A dataset: 2, 5, 5, 6, 8, 9, 11, 15. A value of 25 is added. How does this affect the median?

Accepted Answer

The median increases slightly

Answer

With 8 values the median is (6+8)/2=7; with 9 values it is the 5th value = 8, a slight increase.

Question 5

On a pie chart representing a budget of $2,000, the 'food' sector has a central angle of 72°. How much is budgeted for food?

Accepted Answer

$400

Answer

72° / 360° = 0.20; 0.20 × $2,000 = $400.

Core Academic Skills Assessment Practice Test