Exam 7: Continuous Probability Distributions

A national manufacturer of unattached garages discovered that the distribution of the time for 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 32 and 34 hours to erect?

For any uniform probability distribution,the mean and standard deviation can be computed based on the maximum and minimum values of the random variable.

The distribution of the annual incomes of a group of middle management employees approximated a normal distribution with a mean of $37,200 and a standard deviation of $800. About 68% of the incomes lie between what two incomes?

An analysis of the grades on the first test in History 101 revealed that they approximate a normal curve with a mean of 75 and a standard deviation of 8. The instructor wants to award the grade of A to the upper 10% of the test grades. To the nearest percent,what is the dividing point between an A and a B grade?

The upper and lower limits of a uniform probability distribution are ________.

What is an important similarity between the uniform and normal probability distributions?

The time to fly between New York City and Chicago is uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes. What is the distribution's standard deviation?

What is a normal distribution with a mean of 0 and a standard deviation of 1 called?

The weekly mean income of a group of executives is $1,000 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 z-value for a standard normal distribution ________.

Management is considering a bonus system to increase production. One suggestion is to pay a bonus on the highest 5% of production based on past experience. Past records indicate that an average of 4,000 units of a small assembly is produced during a week. The distribution of the weekly production is approximately normally distributed with a standard deviation of 60 units. If the bonus is paid on the upper 5% of production,the bonus will be paid on how many units or more?

The mean of a normal probability distribution is 500 and the standard deviation is 10. About 95% of the observations lie between what two values?

For a uniformly distributed random variable,x,P(x)is constant.

For a standard normal distribution,what is the probability that z is greater than 1.75?

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

If an average of 60 customers are served per hour,then one customer arrives every ________.

The mean amount spent by a family of four on food is $500 per month with a standard deviation of $75. Assuming that the food costs are normally distributed,what is the probability that a family spends less than $410 per month?

The seasonal output of a new experimental strain of pepper plants was carefully weighed. The mean weight per plant is 15.0 pounds,and the standard deviation of the normally distributed weights is 1.75 pounds. Of the 200 plants in the experiment,how many produced peppers weighing between 13 and 16 pounds?

The center of a normal probability distribution is ________.

For the exponential distribution,the mean and standard deviation are equal.