Question

the accompanying data set lists diastolic blood - pressure measurements (mm hg) of females. all of the values are even numbers. construct a stemplot. identify the two values that are closest to the middle when the data are sorted in order from lowest to highest. (these values are often used to find the median.) 84 72 68 80 94 62 68 94 82 72 92 70 74 66 66 90 66 66 68 74 62 80 90 88 construct the stemplot.

Explanation:

Step1: Organize data in ascending order

62, 62, 66, 66, 66, 66, 68, 68, 70, 72, 72, 74, 74, 80, 80, 82, 84, 88, 90, 90, 92, 94, 94

Step2: Determine number of data points

There are \(n = 22\) data - points.

Step3: Find positions of middle values

For an even - numbered data set, the median is the average of the values at positions \(\frac{n}{2}\) and \(\frac{n}{2}+1\). Here, \(\frac{n}{2}=\frac{22}{2}=11\) and \(\frac{n}{2}+1 = 12\).

Step4: Identify middle values

The 11th value is 72 and the 12th value is 74.

Step5: Construct stemplot

The stemplot:

6 | 2 2 6 6 6 6 8 8
7 | 0 2 2 4 4
8 | 0 0 2 4 8
9 | 0 0 2 4 4

Answer:

The two values closest to the middle are 72 and 74. The stemplot is:

6 | 2 2 6 6 6 6 8 8
7 | 0 2 2 4 4
8 | 0 0 2 4 8
9 | 0 0 2 4 4