Answer:
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