Discrete Math Chapter 9 Test REVIEW
Name___________________________________
Construct a frequency polygon. 1) Score 50-59 60-69 70-79 80-89 90-99
Number of Students 2 8 30 40 10
Use the data to make a histogram. 2) The students in Mrs. Logan's Spanish class received the following grades on a test. Use four intervals starting with 60 - 69. 75 94 87 83 78 72 65 75 82 78 97 72 87 94 72 83 87 95 85 97 69
Solve the problem. Round to the nearest hundredth, if necessary. 3) A major league baseball player got the following number of hits during each year of his career: 55, 112,183, 177, 184, 188, 190, 193, 158, 145, 151, 142, 116, 40. What is the mode of the data? Solve the problem. 4) Using the information in the table on home sale prices in the city of Summerhill for the month of June, find the mean for the grouped data. Sale Price (thousands of dollars) 80.0 - 110.9 111.0 - 141.9 142.0 - 172.9 173.0 - 203.9 204.0 - 234.9 235.0 - 265.9
Frequency 2 5 7 10 3 1
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Find the range for the set of data numbers. 5) 28, 37, 18, 45, 52 Find the standard deviation of the data summarized in the given frequency table. 6) The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results. Find the standard deviation. Round your answer to one decimal place. Waiting time Number of (minutes) customer 0-3 11 4-7 13 8 - 11 11 12 - 15 14 16 - 19 0 20 - 23 1 Find a z-score satisfying the given condition. 7) 20.1% of the total area is to the right of z. Find the percent of the total area under a normal curve that is contained within the specified interval. 8) Between z = -2.36 and z = -.14 A company installs 5000 light bulbs, each with an average life of 500 hours, standard deviation of 100 hours, and distribution approximated by a normal curve. Find the approximate number of bulbs that can be expected to last the specified period of time. 9) More than 740 hours Assume the distribution is normal. Use the area of the normal curve to answer the question. Round to the nearest whole percent. 10) The average runner at a local college runs the mile in 4.5 minutes, with a standard deviation of .3 minutes. What is the probability that a person will run a mile in less than 4 minutes? At one high school, students can run the 100-yard dash in an average of 15.2 seconds with a standard deviation of .9 seconds. The times are very closely approximated by a normal curve. Find the percent of times that are: 11) Less than 15.2 seconds Solve the problem. 12) If the life, in years, of a television set is normally distributed with a mean of 33 years and a standard deviation of 7 years, what should be the guarantee period if the company wants less than 3% of the television sets to fail while under warranty?
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