Question

If there are 18 values in a data set in order from smallest to largest, what is the median of the data set?

A. The mean of the 9th and 10th values
B. The 9th value
C. The 8th value
D. The mean of the 8th and 9th values

Answer 1

a. because the 9th and 10th values are in the middle so you would have to take their average to get the middle number

Answer 2

Answer: The correct option is

(A) The mean of the 9th and 10th values.

Step-by-step explanation: Given that there are 18 values in a data set in order from smallest to largest.

We are to find the median of the data set.

We know that

if a data set has n values, then the median value is given by

`(i)~(n+1)/(2),` if n is odd.

`(ii)\textup{the mean of  }(n)/(2)~\textup{and}~(n)/(2)+1` if n is even.

In the given situation, we have

n = 18, which is even.

So, the median values are given by the mean of

`(18)/(2),~~(18)/(2)+1\\\\=9,~~10.`

Therefore, the required median value is the mean of 9th and 10th values.

Option (A) is CORRECT.