Measures of Spread Iqr

The numbers of runs scored by a softball team in 20 games are given.
 3, 4, 8, 12, 7, 5, 4, 12, 3, 9, 11, 4, 14, 8, 2, 10, 3, 10, 9, 7
What is the Interquartile Range.

• IQR = 6

• IQR = 10

• IQR = 7.5

• IQR = 12

The interquartile range (IQR) of a data set is the difference between the third and first quartiles. It represents the range of the middle half of the data.

• True

• False

Given the data: 136, 150, 119, 150, 125, 143.
Find the interquartile range (IQR)

•  IQR = 150 - 119 = 31

•  IQR = 150 - 125 = 25.

• IQR = 150 - 125 = 75.

•  IQR = 150 - 119 = 31.

A data value x is an outlier if
if:        x < Q 1 - 1.5(IQR)
or if:    x > Q 3 + 1.5(IQR).

• Depends on the data size

• Sometimes true

• Always true

• False

• Mode
• Median
• Mean
• IQR

Which measure of spread should be used to describe the distribution?

• standard deviation

• interquartile range

• range

• median

Because this distribution is ____________ to the ___________, we would use the ______________ for the center and the _____________ for the spread of the data.

• symmetric, middle, median, IQR

• skewed, left, median, IQR

• skewed, left, mean, IQR

• skewed, right, median, standard deviation

Find the IQR of the distribution.

(only type in the number)

Find the interquartile range?

• 8

• 6

• 5

• 4

The IQR is the

• max - min

• Interquartile Range

• measure of spread that pairs with the mean

• Q₃ - Q₁