Question

what is the median of this set of data values? 10, 14, 15, 17, 20, 21, 22, 25
a. 17
b. 18
c. 20
d. 18.5

Explanation:

Step1: Check number of data - points

There are 8 data - points. Since \(n = 8\) (an even number), the median is the average of the \(\frac{n}{2}\)th and \((\frac{n}{2}+ 1)\)th ordered data - points.

Step2: Identify the relevant data - points

\(\frac{n}{2}=\frac{8}{2}=4\) and \(\frac{n}{2}+1 = 4 + 1=5\). The 4th value is 17 and the 5th value is 20.

Step3: Calculate the median

Median\(=\frac{17 + 20}{2}=\frac{37}{2}=18.5\)

Answer:

D. 18.5