Name ____________________________________________ ID # _____________
ORG 205 __________________ Problem Set 1 (25 Points)
1. Categorize the type of sampling (simple random, stratified, systematic, cluster, or convenience) used in each of the following situations. (5 points)
0. _____________________________ To conduct a preelection opinion poll on a proposed amendment to the state constitution, a random sample of 10 telephone prefixes (first three digits of the phone number) was selected, and all households from the phone prefixes selected were called.
0. _____________________________ To conduct a study on depression among the elderly, a sample of 30 patients in one nursing home was used.
0. _____________________________ To maintain quality control in a brewery, every 20th bottle of beer coming off the production line was opened and tested.
0. _____________________________ Subscribers to the magazine Sound Alive were assigned numbers. Then a sample of 30 subscribers was selected by using a random-number table. The subscribers in the sample were invited to rate new compact disc players for a “What the Subscribers Think” column.
1. Almost everyone files (or will sometime file) a federal income tax return. A research poll for Turbo Tax (a computer software package to aid in tax-return preparation) asked what aspect of filing a return people thought to be the most difficult. The results showed that 43% of the respondents said understanding the IRS jargon, 28% said knowing deductions, 10% said getting the right form, 8% said calculating the numbers, and 10% didn’t know. Make a circle graph to display the information. Note: Percentages will not total 100% because of rounding. (5 points)
1. Driving under the influence of alcohol (DUI) is a serious offense. The following data give the ages of random sample of 50 drivers arrested while driving under the influence of alcohol. This distribution is based on the age distribution of DUI arrests given in the Statistical Abstract of the United States (112th Edition).
46 16 41 26 22 33 30 22 36 34
63 21 26 18 27 24 31 38 26 55
31 47 27 43 35 22 64 40 58 20
49 37 53 25 29 32 23 49 39 40
24 56 30 51 21 45 27 34 47 35
1. Make a stem-and-leaf display of the age distribution. (5 points)
1. June purchased a new home computer and has been having trouble with voltage spikes on the power line. Such voltage jumps can be caused by the operation of appliances, such as clothes dryers and electric irons, or just by a power surge on the outside power line. Her friend Jim is an electronics technician and has obtained the following data about voltages when certain electric appliances are turned on and off. Remember, the normal line voltage is 110 volts. All measurements are taken from the line and measured in volts.
73 140 78 142 80 140 90 133
1. Compare the sample mean, sample standard deviation, coefficient of variation, and range. (5 points)
Jim advised June to buy a device called a power surge protector that protects the computer from strong voltage spikes. Using the power surge protector, Jim again measured voltages to the computer when the same appliances were turned on and off. The results in volts were
100 120 108 114 105 117 103 114
1. Professor Cramer determines a final grade based on attendance, two papers, three major tests, and a final exam. Each of these activities has a total of 100 possible points. However, the activities carry different weights. Attendance is worth 5%, each paper is worth 8%, each test is worth 15%, and the final is worth 34%.
1. What is the average for a student with 92 on attendance, 73 on the first paper, 81 on the second paper, 85 on test 1, 87 on test 2, 83 on test 3, and 90 on final exam? (5 points)