Answer:
The mean and standard devaition of W are 6 and 31 respectively.
Step-by-step explanation:
Given that:
W = 7 + 2X
Variance (W) = Variance(7 + 2X)
For a term constant term, the variance is zero.
So;
W = 4 × Var(X)
W = 4 × (SD (X))²
W = 4 × (3)²
W = 4 × 9
W = 36
Thus, Variance (W) = 36
The standard deviation of W =
W =
W = 6
Also;
E(W) = E(7 +2 X)
E(W) = 7 + 2 × E(X)
where;
mean X = 12
E(W) = 7 + 2(12)
E(W) = 31
Thus, the mean and standard devaition of W are 6 and 31 respectively.