At a restaurant that sells appetizers: • 8% of the appetizers cost $1 each, • 20% of the appetizers cost $3 each, • 32% of the appetizers cost $5 each, • 40% of the appetizers cost $10 each, An appetizer is chosen at random, and X is its price. Each appetizer has 7% sales tax. So Y = 1.07X is the amount paid on the bill (in dollars) Find the variance of Y.

Respuesta :

Answer:

12.0 (3 sf)

Step-by-step explanation:

E(X) = 0.08(1)+0.2(3)+0.32(5)+0.4(10)

E(X) = 6.28

E(X²) = .08(1²)+.2(3²)+.32(5²)+.4(10²)

E(X²) = 49.88

Var(X) = E(X²) - [E(X)]²

= 49.88 - 6.28² = 10.4416

Var(1.07X) = 1.07² Var(X)

= 1.1449×10.4416 = 11.95458784

12.0 (3 sf)

Q&A Education