Find the value of x.

13,15,17, x, 20,21; The median is 18.

1

Step-by-step explanation:

13 15 17 x 20 21

Cross out all outer numbers

We are left with 17 and x

With double medians, you add those two together and then divide them by two.

With the median (total) being 18, we will first add 17+x then divide Y/2 = 18

The value of x is 1