The median of the data set is 18. What is the missing number?

The missing number in the data set is 19

Step-by-step explanation:

The data set is given to be : 12, 17, 21, 13, 25

The median of the data set is given to is 18

Now, to find the median first arrange the data set in the increasing order

So, The data set would be : 12, 13, 17, 21, 25

Now, let the missing number be x

So, The total number of terms in the data set will be 6 that is even.

Now, insert the missing number in between

⇒ The data set will become : 12, 13, 17, x, 21, 25

Now, Median = Mean of 3rd and 4th term

⇒ 18 = Mean of 17 and x

⇒ 18 × 2 = x + 17

⇒ x = 19

Therefore, The missing number in the data set is 19