NSAA NSAA Mathematics - Statistics and Probability 3

Question 1

The mode of the data set {4, 7, 7, 3, 4, 7, 9} is:

Accepted Answer

7

Answer

4

Answer

9

Answer

3

Question 2

A box has 3 defective and 7 non-defective items. Two items are drawn without replacement. What is the probability both are defective?

Accepted Answer

1/15

Answer

9/100

Answer

6/90

Answer

3/10

Question 3

Which of the following is the correct definition of standard deviation?

Accepted Answer

The square root of the variance

Answer

The average of all data values

Answer

The square of the variance

Answer

The range divided by 2

Question 4

If a data set has a positive skew, which relationship is typically true?

Accepted Answer

Mode < Median < Mean

Answer

Mean < Median < Mode

Answer

Mean = Median = Mode

Answer

Mean > Mode = Median

Question 5

What is the expected value of a fair six-sided die roll?

Accepted Answer

3.5

Answer

3

Answer

4

Answer

6

Question 6

A scatter plot shows a correlation coefficient of r = -0.9. This indicates:

Accepted Answer

Strong negative correlation

Answer

No correlation

Answer

Weak positive correlation

Answer

Perfect positive correlation