Given that is the mean and is the variance of n observations x1, x2, ...,xn.
Prove that the mean and variance of the observations ax1, ax2, ax3, ...., axn are and , respectively,
The given n observations in the question are x1, x2,…..xn
Also, mean =
And, variance = σ2
We know that,
According to the condition given in the question, if each of the observation is being multiplied by a and the new observation are yi the, we have:
yi = axi
Hence, mean of the observations ax1, ax2,…..axn is a
Now, by substituting the values of xi and in (i), we get:
Hence, the variance of the given observations ax1, ax2,….axn is a2σ2