NJGPA Statistics, Data Analysis, and Probability

Question 1

A data set has the values: 4, 7, 7, 9, 13. What is the mean of this data set?

Accepted Answer

8

Answer

The mean is found by adding all values (4+7+7+9+13=40) and dividing by the count (40÷5=8).

Question 2

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

Accepted Answer

1/2

Answer

There are 5 blue marbles out of 10 total (3+5+2=10), so the probability is 5/10 = 1/2.

Question 3

Which measure of central tendency is most affected by an extreme outlier in a data set?

Accepted Answer

Mean

Answer

The mean uses all values in its calculation, so an extreme outlier pulls it significantly higher or lower.

Question 4

A scatter plot shows a trend where as x increases, y also increases consistently. What type of correlation does this represent?

Accepted Answer

Positive correlation

Answer

When both variables increase together, the data shows a positive correlation.

Question 5

The following scores were recorded: 65, 70, 70, 75, 80, 85, 95. What is the median?

Accepted Answer

75

Answer

When 7 values are listed in order, the median is the 4th value: 65, 70, 70, 75, 80, 85, 95 — so the median is 75.

(NJGPA) New Jersey Graduation Proficiency Assessment Practice Test