Question

QUESTION # 1

Most exhibition shows open in the morning and close in the late evening. A study of Saturday arrival times showed that the average arrival time was 3 hours and 48 minutes after the doors opened, and the standard deviation was estimated at about 58 minutes. Assume that the arrival times follow a normal distribution.

(a) At what time after the doors open will 87% of the people who are coming to the Saturday show have arrived? Round your answer to the nearest number of minutes.
minutes after doors open

(b) At what time after the doors open will only 12% of the people who are coming to the Saturday show have arrived? Round your answer to the nearest number of minutes.
minutes after doors open

(c) Do you think the probability distribution of arrival times for Friday might be different from the distribution of arrival times for Saturday? Explain your answer.

QUESTION # 2

A person's blood glucose level and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution that is approximately normal with mean μ = 90 and standard deviation σ = 30. Note: After 50 years of age, both the mean and standard deviation tend to increase. For an adult (under 50) after a 12-hour fast, find the following probabilities. Round your answers to four decimal places.

(a) x is more than 60


(b) x is less than 110


(c) x is between 60 and 110


(d) x is greater than 125 borderline diabetes starts at 125

QUESTION # 3

Find z such that 5% of the standard normal curve lies to the left of z. Round your answer to three decimal places.
z = ____________________________

QUESTION # 4

Find z such that 93.5% of the standard normal curve lies to the right of z. Round your answer to two decimal places.
z = ___________________________

Answer 1