Question

The average of 7, 20, and X is 20. what is the value of X?

Answer 1

x = 33

Explanation:

we find the "average" of a data set by adding all of the numbers in the data set together, and then dividing by the number of numbers/values present

for example,

the average of 2 and 20

2 + 20 = 22

(there are two numbers, so we divide by 2)

22 / 2 = 11

so, this example has an average of 11

we can apply the same logic to a variable:

we know that

`(20+7+x)/(3)` = 20

We can now solve for x:

`(20+7+x)/(3)` = 20

· 3 ·3 {multiply both sides by 3}

20 + 7 + x = 60 {combine like terms}

27 + x = 60 {subtract 27 from both sides to isolate x}

x = 33

{check answer:
7 + 20 + 33 = 60

60 / 3 = 20 (divided by 3 because we have 3 numbers) }

so, the value of x is 33

(x = 33)

hope this helps!!

Answer 2

33

Explanation:

do it in reverse

there are 3 numbers

average is 20

that means total is 20 times 3 which is

60

7+20+x=60

27+x=60

x=60-27=

33