CHAPTER 7 ASSIGNMENT CONTINUOUS PROBABILITY DISTRIBUTIONS

CHAPTER 7 ASSIGNMENTCONTINUOUS PROBABILITY DISTRIBUTIONSName _________________________________________Part ISection __________ScoreSelect the correct answer and write the appropriate letter in the space provided.______ 1. In a uniform distributiona. 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 isa. a bell-shaped distribution.b.c. symmetric.d.a continuous distribution.all of the above.______ 3. The standard normal probability distributiona. 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 bya. 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 probabilitydistribution bya. finding = n.b. determining that n is greater than 5.Xc. finding zd. finding σ nπ 1 π______ 6. A normal probability distributiona. has at least two peaks.b. is asymptotic.c. increases as X increases.d. is discrete.______ 7. The normal probability distribution can be used to approximate the binomial whena. n is at least 25.b. both n and n(1 ) are greater than 5.c. n(1 p) is larger than 5.d. only when the z-score is above 5.______ 8. What percent of the area under the normal curve is within 1 ?a. 68%.b. 34%.c. 95%.d. none of the above.______ 9. A z valuea. 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.______ 10. The correction for continuity is used whenChapter 7123Continuous Probability DistributionsThe Normal Probability Distributiona. the z-scores are integers.c. the z-scores are less than 0.5Part II11.b.d.the distribution is discrete.the distribution is continuous.Answer the following questions. Be sure to show your work.A statistics instructor collected data on the time it takes the students to complete a test. Thetest taking time is uniformly distributed within a range of 35 minutes to 55 minutes.a. Determine the height and draw this uniform distribution.b. How long does the typical test taking time?b.c. Determine the standard deviation of the test taking time.c.d.What is the probability a particular student will take less than 45 minutes?d.e. What is the probability a particular student will take between 45 and 50 minutes?e.Continuous Probability Distributions124Chapter 712.Fix-It Copiers advertises a mean time of 100 minutes for office calls with a standarddeviation 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.13.e.Twenty percent of their jobs take more than how much time?f.A certain printer cartridge has demonstrated a mean time usage of 9 hours and a standarddeviation of 22 minutes. What time usage guarantee (in hours) should the manufacturerChapter 7125Continuous Probability Distributions13.The Normal Probability Distributionadvertise in order to ensure that only 4% of the cartridges fail to meet the guaranteed timeusage?15.A clothing store asserts that 60% of its customers pay by credit. On a particular day, 35customers purchased items at the store.a. What is the mean and standard deviation of the binomial distribution?a.b. What is the probability that half (18 or more) of the customers paidby credit?c. What is the probability that 30 or more paid by credit?b.c.d. What is the probability that less than 12 paid by credit?d.Continuous Probability Distributions126Chapter 7e. What is the probability that 12 to 30 paid by credit?e.16.Suppose that gas mileage for a 2006 Eco is uniformly distributed random variable between 40and 44 miles per gallon.a. What is the probability that the gas mileage exceeds 43 miles per gallon?a.b. What is the probability that gas mileage will be between 41 and 43 miles per gallon?b.c . What is the expected gas mileage for Ecko?c.Chapter 7127Continuous Probability DistributionsThe Normal Probability Distribution