Question

If a is the average (arithmetic mean) of 4x and 7, b is the average of 5x and 6, and c is the average of 3x and 11, what is the average of a, b, and c, in terms of x?

Answer 1

2x+4

Explanation:

Given that a is the average (arithmetic mean) of 4x and 7, b is the average of 5x and 6, and c is the average of 3x and 11

By definition of arithmetic mean,

we have
`a=(4x+7)/(2) \\b=(5x+6)/(2) \\c=(3x+11)/(2)`

Let us calculate sum of a,b,c in terms of x

a+b+c =
`(4x+7+5x+6+3x+11)/(2) \\=6x+12`

Average = sum/3 =
`(6x+12)/(3) =2x+4`