The taxi and takeoff time for commercial jets is random variable x with a mean of 8.4 minutes and a standard deviation of 3.3 minutes assume that the distribution of taxi and takeoff times is approximately normal you may assume that the jets are lined up on a runway so that one taxies and takes off immediately after the other and that they take off one at a time on a given runway what is the probability that for 40 jets on a given runway total taxi and takeoff time will be less than 320 minutes?

The average number of shoppers at a particular grocery store in one day is 505, and the standard deviation is 115. The number of shoppers is normally distributed. For a random day, what is the probability that there are between 200 and 400 shoppers at the grocery store? The answer should be typed as a decimal with 4 decimal places.

An elevator has a play card stating that the maximum capacity is 1980 pounds 12 passengers so 12 adult male passages can have a mean way of up to 1180÷12 = 165 pounds. If the elevator is loaded with 12 adult male passengers, find the probability that it is overloaded because they have a mean weight greater than 165 lb. Assume that weights of males are normally distributed with a mean of 172 pounds and a standard deviation of 27 pounds. Does this elevator appear to be safe?

Suppose that you are designing an instrument panel for a large industrial machine. The machine requires the person using it to reach 2 feet from a particular position. The reach from this position for adult women is known to have a mean of 2.7 feet with a standard deviation of 0.5. The reach for adult men is known to have a mean of 3.1 feet with a standard deviation of 0.7. Both women's and men's reach from this position is normally distributed. If this design is implemented, (a) what percentage of women will not be able to work on this instrument panel? (b) What percentage of men will not be able to work on this instrument panel? (c) Explain your answers to a person who has never had a course in statistics. Click here to view page 1 of the table. Click here to view page 2 of the table. Click here to view page 3 of the table. Click here to view page 4 of the table.

A data from a physician office shows that only 10% of patients are taller than 6 ft. If there are 4 patients in the office,find the probability that at least one of them is taller than 6 ft. Then, find mean and standard deviation of the number of patients taller than 6ft.

The life of light bulbs is distributed normaly, The variance of the lifetime is 900 and the mean lifetime of a bulb is 550 hours. Find the probablty of abulb lasting forat least 583 hours. Round your anvwer to four decimal places

he average amount of time boys and girls  spend playing sports each week is believed to be the same. A sample of equal size n is taken from boys and girls , the mean of the boys is 29 hours  with standard deviation 4  hours and the mean of the girls  is 27 hours with standard deviation 3 hours Both populations have a normal distribution. The calculated value is  1.2       n =

Procter and Gamble reported that an American family of four washes an average of 2000 pounds of clothes each year. If the standered deviation of the distribution is 187.5 pounds, find the probability that the mean of a randomly selected same of 50 families of 4 will be less that 1950 pounds. Round your awnser to four decimal places and assume the variable is normally distributed

The length of the western rattlesnake is normally distributed with a mean of 42 inches and a standard deviation of 2.04 inches. Let X be the length of one of these snakes selected at random. Determine the probability that the snake is longer than 45 inches. Report your answer to four decimal places (like .1567).