Question

The average of 10 numbers is -5. A new number is added to the list making the average -6. What is the new number?

Answer 1

Answer:

- 16

Step-by-step explanation:

Average is calculated as

average = $\frac{total}{count}$

Thus for the given 10 numbers we have

$\frac{total}{10}$ = - 5 ( multiply both sides by 10 )

total = - 50

let the number added be x, then

$\frac{total+x}{11}$ = - 6 ( multiply both sides by 11 )

total + x = - 66, that is

- 50 + x = - 66 ( add 50 to both sides )

x = - 16

The new number is - 16