CHAPTER 7 ASSIGNMENT CONTINUOUS PROBABILITY DISTRIBUTIONS Name Ashleigh Posey Part I Section __________ Score ______ Select the correct answer and write the appropriate letter in the space provided. ______ 1. In a uniform distribution a. the mean and the median are always equal. b. the mean and the standard deviation are always equal. c. the mean is always larger than the median. d. the mean is always smaller than the median. ______ 2. The normal probability distribution is a. a bell-shaped distribution. c. symmetric. b. d. a continuous distribution. all of the above. ______ 3. The standard normal probability distribution a. is a special case of the normal probability distribution. b. has a mean equal to 0 and a standard deviation equal to 1. c. measures the distance from the mean in units of the standard deviation. d. all of the above. ______ 4. A normal probability distribution is completely described by a. its mean. b. its standard deviation. c. its mean and standard deviation. d. none of the above. ______ 5. Any normal probability distribution can be converted to a standard normal probability distribution by a. finding = n. b. determining that n is greater than 5. X c. finding z d. finding n 1 ______ 6. A normal probability distribution a. has at least two peaks. b. is asymptotic. c. increases as X increases. d. is discrete. ______7. Part II A z value a. is the standard deviation for the standard normal probability distribution. b. is a measure of how many standard deviations the mean is from the median. c. is the difference of the mean and the probability of z. d. is a measure of how many standard deviations a particular score is from the mean. Answer the following questions. Be sure to show your work. Chapter 7 123 Continuous Probability Distributions The Normal Probability Distribution 8. Fix-It Copiers advertises a mean time of 100 minutes for office calls with a standard deviation of 25 minutes. What percentage of calls are completed: a. between 100 and 120 minutes? a. b. in less than 120 minutes? b. c. in less than 60 minutes? c. d. between 120 and 150 minutes? d. e. between 60 and 120 minutes? f. e. Twenty percent of their jobs take more than how much time? Chapter 7 124 f. Continuous Probability Distributions The Normal Probability Distribution