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

$A=\frac{x+y+z}{3}$

We will complete the given table

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

$A=\frac{7+12+8}{3}=\frac{27}{3}=9$

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

$A=\frac{23+17+2}{3}=\frac{42}{3}=14$

For the last case,

x = 4 , y = 11 , A = 6

$6=\frac{4+11+z}{3}$

Solve for z, multiply both sides by 3

$\begin{gathered} 6\cdot3=\frac{4+11+z}{3}\cdot3 \\ 18=4+11+z \\ 18=15+z \\ \\ z=18-15=3 \end{gathered}$