Question

Ralph’s Bookstores have indicated that the annual gross revenue for their stores is µ=$250,000 with a standard deviation of σ=$50,000.

Blank #1 (a): Find the probability that the annual gross revenue is more than $260,000. Report your answer to 4 decimal places. If this is a probability that cannot be determined, then state unknown as your answer.

Blank #2 (b): A random sample of 25 stores is chosen. Find the probability that the mean annual gross revenue is more than $260,000. Report your answer to 4 decimal places. If this is a probability that cannot be determined, then state unknown as your answer.

Blank #3 (c): A random sample of 40 stores is chosen. Find the probability that the mean annual gross revenue is more than $260,000. Report your answer to 4 decimal places. If this is a probability that cannot be determined, then state unknown as your answer.

Blank #4 (d): If the sample size were to increase, how would the probability compare to what you found in part (c)? (smaller, larger, equal).

The number of Girl Scout cookies sold by each of the girl scouts in Central City has a distribution that is approximately normal with µ = 100 boxes and a standard deviation σ = 40 boxes.

2: Blank #1 (a): Find the probability that a girl scout chosen at random sold between 80 and 120 boxes. Report your answer to 4 decimal places. If this is a probability that cannot be determined, then state unknown as your answer.

Blank #2 (b): Find the probability that the mean number of cookies sold by a random sample of 36 scouts is between 80 and 120 boxes. Report your answer to 4 decimal places. If this is a probability that cannot be determined, then state unknown as your answer.

Please explain how to do it clearly.

Answer 1