Question

Find the median of the following data:

9, 15, 17, 18, 6, 20, 8, 5, 18, 18, 10, 5, 14, 12, 10,7

A. 18
B. 12
C. 11
D. 15

Answer 1

Answer: C

Explanation:

To find the median, arrange the numbers in sequential order.

5, 5, 6, 7, 8, 9, 10, 10, 12, 14, 15, 17, 18, 18, 18, 20

When there are an odd number of data in the set, choose the middle number in the set. For example, see the following data set.

2, 4, 6, 8, 9

The middle number in the data set is 6, so it is the median.

When there is an even number of data in the set, choose the middle two numbers, add them together, and then divide them by 2.

There are 16 numbers in this data set. We need to find the two middle numbers in the set.

5, 5, 6, 7, 8, 9, 10, 10, 12, 14, 15, 17, 18, 18, 18, 20

10 and 12 are the two middle numbers in the set.

10 + 12 = 22

22/2 = 11

Median = 11

Answer 2

18

Explanation:

The median of a set of data is the value that separates the lower and upper halves of the data. To find the median, the data must be arranged in numerical order.

The data, arranged in numerical order, is:

5, 5, 6, 7, 8, 9, 10, 10, 12, 14, 15, 17, 18, 18, 18, 20

Since the number of data points is an odd number (17), the median is simply the middle value, which is:

18

So the correct answer is A) 18.