Question

The highest temperatures measured at Death Valley, California, from 1995 to 2004 are given as a dataset.

127, 125, 125, 129, 123, 126, 127, 128, 128, 125

Find the range and the interquartile range of the dataset.

Answer 1

To find the range, we subtract the minimum value from the maximum value:

Range = Maximum value - Minimum value
Range = 129 - 123
Range = 6

So, the range of the dataset is 6.

To find the interquartile range, first we need to find the first quartile (Q1) and the third quartile (Q3).

To find Q1, we first need to find the median of the lower half of the data set:
125, 125, 123
Median = 125

To find Q3, we need to find the median of the upper half of the data set:
127, 128, 128
Median = 128

Now we can calculate the interquartile range (IQR):

IQR = Q3 - Q1
IQR = 128 - 125
IQR = 3

So, the interquartile range of the dataset is 3.