Question

1. The average of five numbers is 42 while the average of another eight numbers is 81. What is the combined average of all numbers together?

please give me an answer with also explain it.

Answer 1

Answer is in the attachment.

Answer 2

The combined average of all numbers together is 66.

Step-by-step explanation:

Formula for Average:

$Average=\frac{\sum x}{n}$

where, n is number of observations.

It is given that the average of five numbers is 42

$Average=\frac{\text{Sum of 5 terms}}{5}$

$42=\frac{\text{Sum of 5 terms}}{5}$

Multiply both sides by 5.

$210=\text{Sum of 5 terms}$

The average of another eight numbers is 81.

$Average=\frac{\text{Sum of 8 terms}}{8}$

$81=\frac{\text{Sum of 8 terms}}{8}$

Multiply both sides by 8.

$648=\text{Sum of 8 terms}$

Sum of 13 terms = Sum of 5 terms + Sum of 8 terms

                          = 210 + 648

                          = 858

No. of observations = 5 + 8 =13

Combined average of all numbers together is

$Average=\frac{858}{13}=66$

Therefore, the combined average of all numbers together is 66.

#Learn more

The given data is 46 ,52,48,11,41,62,54,98,44 find the average of given data.

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