Question

eight Row in the table below gives you a number x a number Y and either a third number Z or the average pay of the three numbers that have which of the three numbers is given by a equals x + y + z / 3 fill in the missing numbers

Answer 1

Given three numbers x, y and z

The average of the numbers = A

`A=(x+y+z)/(3)`

We will complete the given table

When : x = 7 , y = 12 , z = 8

`A=(7+12+8)/(3)=(27)/(3)=9`

When x = 23 , y = 17 , z = 2

`A=(23+17+2)/(3)=(42)/(3)=14`

For the last case,

x = 4 , y = 11 , A = 6

`6=(4+11+z)/(3)`

Solve for z, multiply both sides by 3

`\begin{gathered} 6\cdot3=(4+11+z)/(3)\cdot3 \\ 18=4+11+z \\ 18=15+z \\ \\ z=18-15=3 \end{gathered}`