Answer:
5.20
Step-by-step explanation:
X : ______ 8 ____ - 4
P(X) : ___ 0.75 __ 0.25
The expected mean E(x) :
E(x) = ΣX / n
n = sample size = 2
E(x) = (8*0.75) + (-4*0.25)
E(x) = 6 - 1
E(x) = 5
The standard deviation : sqrt(Var(x))
Var(x) = Σx²p(x) - E(x)²
Var(x) = (8^2 * 0.75) + (-4^2 * 0.25)) - 5^2
Var(x) = ((64 * 0.75) + (16* 0.25)) - 25
Var(x) = (48 + 4) - 25
Var(X) = 27
Standard deviation = sqrt(27)
Standard deviation (x) = 5.1961524
Standard deviation = 5.20
