Question

solve and explain step by step ​

Answer 1

Answer:

mn

Step-by-step explanation:

$average=\frac{total sum of all observations}{no. of all observations}$

$total sum=(no. of all observations) * average$

total sum of m no. = m * n² = mn²

total sum of n no. = n * m² = nm²

$average of (m+n) no.=\frac{total sum of (m+n) no.}{(m+n)}$

average of (m+n)=$\frac{mn^{2}+nm^{2}}{m+n} =\frac{mn(m+n)}{m+n}$

average of (m+n)=mn