A study shows that the normal time that a customer occupied a table in a fine diningrestaurant is 1.2 hours with a standard deviation of 30 minutes. A food entrepreneur wants to find the probability that customers occupying 25 tables would have an average time of less than 1 hour.

The green turtle migrates across the Southern Atlantic in the winter, swimming great distances. A study found that the mean migration distance was 2,200 kilometers and the standard deviation was 625 kilometers. Assume that the distances are normally distributed. Find the probability that a randomly selected green turtle migrates a between 1,900 kilometers and 2,200 kilometers.

For a certain type of smart phone the length of time between charges of the battery is normally distributed with a mean of 50 hours and a standard deviation of 15 hours. John owns one of these smart phones and wants to know the probability that the length of time between charges will be between 50 and 70 hours.

The height of 10 year old females is normally distributed with a mean of 54.8 inches and a standard deviation of 2.74 inches. If a random 10 year old female is chosen at random, find the probability her height is between 53 inches and 57 inches.

Suppose that heights of women at UT Tyler are normally distributed with a mean of 64 inches and a standard deviation of 2.4 inches.    Find the probability that a collection of 16 women have an average height less than 62 inches tall.

The producer of a weight-loss pill advertises that people who use the pill lose, after one week, an average (mean) of 1.85 pounds with a standard deviation of 1.02 pounds. In a recent study, a group of 55 people who used this pill were interviewed. The study revealed that these people lost a mean of 1.88 pounds after one week. If the producer's claim is correct, what is the probability that the mean weight loss after one week on this pill for a random sample of 55 individuals will be 1.88 pounds or less? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places. Check esc @ %23 y e tab

In a recently conducted study, families reported using an average of 70 gallons of gasoline per month with a standard deviation of 8 gallons. If a family is chosen at random, what is the probability that it uses between 61 and 79 gallons of gasoline per month? Assume the data is normally distributed.

The life of a vacuum cleaner is normally disyributed with mean 5 years and standard deviation 2 year. find the probability that it lasts less than 4 years.

The lengths of human pregnancies are approximately normally distributed with a mean of 268 days and a standard deviation of 16 days. What is the probability that pregnancy lasts between 240 and 280 days?

A report claimed that children between the ages of 2 and 5 watch an average of 25 hours of television per week. Assuming the variable is normally distributed and the standard deviation is 3 hours. If 40 children between the ages of 2 and 5 are randomly selected, find the probability that the mean of the number of hours they watch television will be greater than 26.3 hours.