Question

The average of 21, 18, 16 and x is 20. what is the value of x?

Answer 1

21.75

Explanation:

21- 16 = 5

5/2 2.5

16 + 2.5 or 21 - 2.5

18.5 - 18 = .5

1/2 times 1/2 =

1/4

1/4 = .25

18.5 - .25 or 18 + .25

18.25

20 - 18.25 = 1.75

1.75 + 20

21.75

Answer 2

Answer: 25

Step-by-step explanation:

21 + 18 +16 + X = 20×4

55 + X = 80

X = 80- 55