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three of four numbers have a sum of 22. If the average of the four numbers is 8, what is the fourth number?

Please don't just answer, tell me HOW to answer. I think I just need help setting up the correct equation

Respuesta :

nlewing0307
the answer is 10.

if you add 4 numbers that average 8, then they must all add up to 32, because 32/4 = 8. so if three of them add up to 22, then the fourth value must be 10.

hope that helped
brainliest is appreciated :D
meshin29
Let a b c d - 4 numbers
a + b + c = 22
(a + b+ c+d)/4 = 8
multiply 4 on both sides of 2nd equation so it will be like this:
a + b + c + d = 32

We all know that sum of a b c is 22 so replace a + b + c on the equation
22 + d = 32
d = 32 - 22
d = 10