Question

An appliance dealer sells three different models of upright freezers having 13.5, 15.9, and 19.1 cubic feet of storage. Let X = the amount of storage space purchased by the next customer to buy a freezer. Suppose that X has pmf:

Answer 1

a) E(X) = 16.09 ft³

E(X²) = 262.22 ft⁶

Var(X) = 3.27 ft⁶

b) E(22X) = 354 dollars

c) Var(22X) = 1,581 dollars

d) E(X - 0.01X²) = 13.470 ft³

Explanation:

The complete Correct Question is presented in the attached image to this solution.

a) Compute E(X), E(X2), and V(X).

The expected value of a probability distribution is given as

E(X) = Σxᵢpᵢ

xᵢ = Each variable in the distribution

pᵢ = Probability of each distribution

Σxᵢpᵢ = (13.5×0.20) + (15.9×0.59) + (19.1×0.21)

= 2.70 + 9.381 + 4.011

= 16.092 = 16.09 ft³

E(X²) = Σxᵢ²pᵢ

Σxᵢ²pᵢ = (13.5²×0.20) + (15.9²×0.59) + (19.1²×0.21)

= 36.45 + 149.1579 + 76.6101

= 262.218 = 262.22 ft⁶

Var(X) = Σxᵢ²pᵢ - μ²

where μ = E(X) = 16.092

Σxᵢ²pᵢ = E(X²) = 262.218

Var(X) = 262.218 - 16.092²

= 3.265536 = 3.27 ft⁶

b) E(22X) = 22E(X) = 22 × 16.092 = 354.024 = 354 dollars to the nearest whole number.

c) Var(22X) = 22² × Var(X) = 22² × 3.265536 = 1,580.519424 = 1,581 dollars

d) E(X - 0.01X²) = E(X) - 0.01E(X²)

= 16.092 - (0.01×262.218)

= 16.0926- 2.62218

= 13.46982 = 13.470 ft³

Hope this helps!!!