Question

The median of the following data: 1, 4, 7, 3, 9, 5, 3, 2, 7, 5.

• A. 4
• B. 4.5
• C. 5
• D. 7

Answer 1

The correct option is B

4.5

For finding the median, the data should be arranged in ascending or descending order first.
After arranging in ascending order, the data becomes:
1, 2, 3, 3, 4, 5, 5, 7, 7, 9.
Now, in order to obtain the median of a given set of observations we need to first check whether the

number of observations are odd or even . If it is odd then median is simply the value of $(\frac{n+1}{2}{)}^{th}$ term

and if it is even then median is the mean value of $(\frac{n}{2}{)}^{th}$ and ($\left(\frac{n}{2}\right)+1{)}^{th}$ term. Here the number
of observations is even, so we have the median as mean value of fifth and sixth observations which are 4 and 5 respectively
i.e. $\left(\frac{4+5}{2}\right)$ = 4.5
Hence, median of the given data = 4.5