Answer to Question #43902 in Management for venotini

Question

Question 4
Refer to Question 3. How long do the longest 10% of calls last?

Question 5
The lifetimes of light bulbs that are advertised to last for 5,000 hours are normally distributed with a mean of 5,100 hours and a standard deviation of 200 hours. What is the probability that a bulb lasts longer than the advertised figure?

Question 6
Refer to Question 5. If we wanted to be sure that 98% of all bulbs last longer than the advertised figure, what figure should be advertised?

Question 7
Travelbyus is an Internet-based travel agency wherein customers can see videos of the cities they plan to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400.
a. What is the probability of getting more than 12,000 hits?
b. What is the probability of getting fewer than 9,000 hits?

Question 8
University and college students average 7.2 hours of sleep per night, with a standard deviation of 40 minutes. If the amount of sleep is normally distributed,
a. What proportion of university and college students sleep for more than 8 hours?
b. Find the amount of sleep that is exceeded by only 25% of students.