Question

If the arithmetic mean of a set of 10 values is 100. If a value 55 is added, then calculate the new arithmetic mean of these 11 values

Answer 1

A.M of 10 values = 100
A.M (avg) = Sum total/Number of values
100 = sum  total/10
Sum total = 100*10 = 1000
Value added = 55
New sum total = 1000+55 = 1055
A.M = sum total/number = 1055/11 = 95.91(approx.)
Hope it helps.

Answer 2

Answer:

The new mean is 95.9

Step-by-step explanation:

Formula for arithmetic mean is

$AM=\frac{\text{Sum of values}}{\text{total number of values}}$

Now, it has been given that arithmetic mean of a set of 10 values is 100. Hence, we have

$100=\frac{\text{Sum of values}}{10}\\\\\text{Sum of values}=1000$

Now, 55 is added to these values, then we have

$AM=\frac{\text{Sum of values+55}}{11}\\\\AM=\frac{1000+55}{11}\\\\AM=\frac{1055}{11}\\\\AM=95.9$

Hence, the new mean is 95.9