Exercise 8 Page 330

To begin creating our box plot, let's order the given values from least to greatest. 15,16,16,18,25,25,26,26,28,28 Now, we have to identify five important values. These are the median, the quartiles, and minimum and maximum values. Let's start with the median.

Identifying the Median

The median is the middle value in a set when the values are arranged in numerical order. If there is an even number of values in a set, there will be two values in the middle. This is the case for our data. 15,16,16,18,25, 25_(median),26,26,28,28 Whenever we have two middle values, we need to calculate their mean in order to find the median!

The median of the set is 25.

Identifying the Quartiles

The first quartile, Q_1, is the median of the lower half of the set and the third quartile, Q_3, is the median of the upper half of the set. 15,16, 16,18,25, | 25,26, 26,28,28 Thus, we can identify Q_1=16 and Q_3=26.

Identifying the Minimum and Maximum Values

When the values are arranged in numerical order, the minimum value is the first value in the set and the maximum value is the last value in the set. 15,16,16,18,25,25,26,26,28, 28 The mininmum value is 15 and the maximum value is 28. Now, we have everything we need to draw the box plot.

Creating the Box Plot

In order to construct the box plot, we will draw a number line and indicate the values of each of the five needed values.