Exam 7: Continuous Probability Distributions

A national manufacturer of unattached garages discovered that the distribution of the lengths of time it takes two construction workers to erect the Red Barn model is normally distributed with a mean of 32 hours and a standard deviation of 2 hours.What percent of the garages take between 30 and 34 hours to erect?

The standard deviation of any uniform probability distribution is

The mean score of a college entrance test is 500;the standard deviation is 75.The scores are normally distributed.What percent of the students scored below 320?

The total area of a normal probability distribution is

In an illustration of a normal probability distribution,a shaded area represents

Tables of normal distribution probabilities are found in many statistics books.These probabilities are calculated from a normal distribution with

For any continuous probability distribution,the probability,P(x),of any value of the random variable,X,can be computed.

Some normal probability distributions are positively skewed.

Which of the following is NOT true regarding the normal distribution?

The mean of a normally distributed group of weekly incomes of a large group of executives is $1,000 and the standard deviation is $100.What is the z-score for an income of $1,100?

The weekly mean income of a group of executives is $1000 and the standard deviation of this group is $100.The distribution is normal.What percent of the executives have an income of $925 or less?

The upper and lower limits of a uniform probability distribution are

A large manufacturing firm tests job applicants who recently graduated from college.The test scores are normally distributed with a mean of 500 and a standard deviation of 50.Management is considering placing a new hire in an upper level management position if the person scores in the upper 6 percent of the distribution.What is the lowest score a college graduate must earn to qualify for a responsible position?

The uniform probability distribution is symmetric about the mean and median.

The formula for the z-score or z-value is (X - µ)/ $\sigma$ .

A random variable from an experiment where outcomes are normally distributed

What is the area under the normal curve between z = 0.0 and z = 1.79?

The shape of any uniform probability distribution is

What type of probability distribution is the normal distribution? ______________

A study of a company's practice regarding the payment of invoices revealed that an invoice was paid an average of 20 days after it was received.The standard deviation equaled five days.Assuming that the distribution is normal,what percent of the invoices were paid within 15 days of receipt?