Question

if the average of 6th observation is 42 and another 6th observation is 45 find the average of 12 observation​

Answer 1

Answer:

The mean of 12 observations is 43.5

Step-by-step explanation:

The formula to compute the combined mean is: $\bar X=\frac{n_{1}\bar x_{1}+n_{2}\bar x_{2}}{n_{1}+n_{2}}$

The average of n₁ = 6 observations is μ₁ = 42.

The average of n₂ = 6 observations is μ₂ = 45.

Compute the combined mean of 12 observations as follows:

$\bar X=\frac{n_{1}\bar x_{1}+n_{2}\bar x_{2}}{n_{1}+n_{2}}\\=\frac{(6\times42)+(6\times45)}{6+6}\\=43.5$

Thus, the mean of 12 observations is 43.5.