Distribution table :
X : ___ 1 _____ 2 _____ 3 ______ 4
P(x) __0.50 __0.25 __ 0.15 ____ 0.10
Answer:
1.85 ; 1.014 ;` 0.55 ; 3.042
Step-by-step explanation:
Probability distribution :
X : ___ 1 _____ 2 _____ 3 ______ 4
P(x) __0.50 __0.25 __ 0.15 ____ 0.10
The mean: E(x) = Σ(X * p(x))
(1*0.5) + (2*0.25) + (3*0.15) + (4 *0.10)
= 1.85
Standard deviation = sqrt(Var(x))
Var(x) = Σ(x²*p(x)) - E(x)²
Var(x) = ((1^2*0.5) + (2^2*0.25) + (3^2*0.15) + (4^2 *0.10)) - 1.85^2
= 4.45 - 3.4225
= 1.0275
Standard deviation = sqrt(1.0275)
Standard deviation = 1.0136567
Standard deviation(X) = 1.014
3.)
Cost of spin = $5
Amount, y to be received = 3 times the number that appears
y = 3x - cost of playing
y = 3x - 5
E(y) = E(3x - 5)
E(y) = E(3x) - 5
Recall :E(x) = 1.85
E(y) = 3(1.85) - 5
E(y) = 0.55
Standard deviation :Sd(y) =
Sd(3x - 5)
3(1.014)
= 3.042
