Points more than $$1.5 \times IQR$$ above $$Q_3 or $$below $$Q_1.$$

Yes, because $$-2 \u003c Q_1$ - 1.5 \times IQR$$

Question 1

Which of the following best describes how to find the median of a data set with an even number of observations?

Accepted Answer

Order the data and take the average of the two middle values.

Question 2

Given the ordered data set: 2, 4, 5, 7, 9, 11, what is the median?

Accepted Answer

$$\frac{5+7}{2} = 6$$

Question 3

Which of the following statements about the interquartile range (IQR) is correct?

Accepted Answer

IQR is the distance between the lower and upper quartiles.

Question 4

If $$Q_1 = 3$ and Q_3$ = 9$$, what is the interquartile range (IQR)?

Accepted Answer

$$IQR = Q_3$ - Q_1$ = 6$$

Question 5

Which of the following is NOT a property of the median?

Accepted Answer

It is affected by extreme values (outliers).

Question 6

In a boxplot, what does the length of the box represent?

Accepted Answer

The interquartile range (IQR).

Question 7

How are outliers identified in a boxplot?

Accepted Answer

Points more than $$1.5 	imes IQR$$ above $$Q_3 or $$below $$Q_1.$$

Question 8

A data set has $$Q_1 = 4$, Q_3$ = 10$$, and the maximum value is 18. Which value would be considered an outlier?

Accepted Answer

$$18$$

Question 9

Which of the following best describes the range covered by the IQR?

Accepted Answer

The range of the middle 50% of the observations.

Question 10

Which step is NOT part of constructing a boxplot?

Accepted Answer

Draw a line at the mean value.

Question 11

Given the following ordered data: 1, 2, 3, 4, 5, 6, 7, 8, 9, what is the median?

Accepted Answer

$$5$$

Question 12

If a data set has $$Q_1 = 2$, Q_3$ = 8$$, and a value of $$-2$$, is $$-2 an $$outlier?

Accepted Answer

Yes, because $$-2 \u003c Q_1$ - 1.5 	imes IQR$$

Question 13

Which of the following is true about the median and IQR?

Accepted Answer

Both are resistant to outliers.

Question 14

A boxplot shows a long right whisker. What does this indicate about the data?

Accepted Answer

The data are right-skewed.

Measures of Central Tendency and Spread: Median, IQR, and Boxplots

Study Guide - Practice Questions