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Fast Service Store has maintained daily sales records on the various size \"Cool

ID: 2900896 • Letter: F

Question

Fast Service Store has maintained daily sales records on the various size "Cool Drink" sales.

"Cool Drink" Price Number Sold

$0.50 75

$0.75 120

$1.00 125

$1.25 80

Total 400

Assuming that past performance is a good indicator of future sales,

(a) what is the probability of a customer purchasing a $1.00 "Cool Drink?"

(b) what is the probability of a customer purchasing a $1.25 "Cool Drink?"

(c) what is the probability of a customer purchasing a "Cool Drink" that costs greater than or equal to $1.00?

(d) what is the expected value of a "Cool Drink"?

(e) what is the variance of a "Cool Drink"?

Explanation / Answer

(a) P = 125/400 = 0.3125

(b) P = 80/400=0.2

(c) P = (125+80)/400 = 0.5125

(d) Expected Value = Mean = {(0.5*75)+(0.75*120)+(1*125)+(1.25*80)}/400 = $0.8925

(e) Variance = {(0.5-0.8925)^2}*75 + {(0.75-0.8925)^2)*120 + {(1.0-0.8925)^2}*125 + {(1.25-0.8925)^2}*80 = 25.66075