Answer: convenience sampling 1. Identify the sampling technique used to 1. Identify the sampling technique used to obtain a sample: Of all the fishermen on a obtain a sample: Of all the fishermen on a lake, lake, the game warden chooses to check the the game warden chooses to check the fishing fishing license only of the first person that license only of the first person that returns to the returns to the boat dock. boat dock.
Math 105 Exam #3
Answer: systematic sampling 2. Identify the sampling technique used to 2. Identify the sampling technique used to obtain a sample: A game warden chooses to obtain a sample: A game warden chooses to check for fishing licenses in every 5th boat he check for fishing licenses in every 5th boat he encounters on his patrol. encounters on his patrol.
Math 105 Exam #3
Answer: cluster sampling 3. Identify the sampling technique used to 3. Identify the sampling technique used to obtain a sample: In order to determine the obtain a sample: In order to determine the expected number of broken eggs per carton, an expected number of broken eggs per carton, an egg packaging worker selects a group of 40 egg packaging worker selects a group of 40 cartons that come off a particular conveyor belt cartons that come off a particular conveyor belt and counts the number of broken eggs within and counts the number of broken eggs within these cartons. these cartons.
Math 105 Exam #3
Answer: stratified sampling 4. Identify the sampling technique used to 4. Identify the sampling technique used to obtain a sample: A group of people are obtain a sample: A group of people are classified according to height and then random classified according to height and then random samples of people from each group are taken. samples of people from each group are taken.
Math 105 Exam #3
Answer: the probability of getting a “tails” is 50%, 5. Tell what possible misuses of regardless of what the previous flips were misinterpretations may exist for the 5. Tell what possible misuses of following statement: While flipping a coin, misinterpretations may exist for the Meghann has gotten five “heads” in a row. following statement: While flipping a coin, Therefore, the next flip will very likely be a Meghann has gotten five “heads” in a row. “tails.” Therefore, the next flip will very likely be a “tails.”
Math 105 Exam #3
Answer: There are many more adult drivers than teenage 6. Tell what possible misuses of drivers, so it is reasonable that more adults have misinterpretations may exist for the accidents. following statement: More adults than 6. Tell what possible misuses of teenagers are involved in automobile accidents misinterpretations may exist for the each year. Therefore, teenagers are better following statement: More adults than drivers than adults. teenagers are involved in automobile accidents each year. Therefore, teenagers are better drivers than adults.
Math 105 Exam #3
Answer: Average values give no information at all about 7. Tell what possible misuses of the range of values in the population. misinterpretations may exist for the 7. Tell what possible misuses of following statement: The average yearly misinterpretations may exist for the income in the U.S. is $29,000. Therefore, following statement: The average yearly everyone in the U.S. is financially secure. income in the U.S. is $29,000. Therefore, everyone in the U.S. is financially secure.
Math 105 Exam #3
Answer: Statistical probabilities do not guarantee the 8. Tell what possible misuses of outcome of a specific sampling. misinterpretations may exist for the 8. Tell what possible misuses of following statement: Four out of five people misinterpretations may exist for the have at least one sinus infection during their following statement: Four out of five people lives. Thus, in a family of five, exactly four have at least one sinus infection during their members are guaranteed to have a sinus lives. Thus, in a family of five, exactly four infection. members are guaranteed to have a sinus infection.
Math 105 Exam #3
Answer: The statistics ignore the effect of safer 9. Tell what possible misuses of automobiles and mandatory seat belt laws. misinterpretations may exist for the 9. Tell what possible misuses of following statement: Annual traffic fatalities misinterpretations may exist for the were higher in the 1970s with interstate speeds following statement: Annual traffic fatalities of 55 miles per hour than in the 1990s when were higher in the 1970s with interstate speeds interstate speeds were 65 miles per hour. of 55 miles per hour than in the 1990s when Therefore, the faster you drive, the safer you will interstate speeds were 65 miles per hour. be. Therefore, the faster you drive, the safer you will be.
Math 105 Exam #3
Answer: 12-16 10. Use the following frequency distribution to 10. Use the following frequency distribution to determine the modal class (or classes). determine the modal class (or classes). Class Frequency Class Frequency 7-11 4 7-11 4 12-16 8 12-16 8 17-21 5 17-21 5 22-26 2 22-26 2 27-31 6 27-31 6 32-36 3 32-36 3
Math 105 Exam #3
Answer: 55.0 11. Use the following frequency distribution to 11. Use the following frequency distribution to determine the midpoint of the sixth class. determine the midpoint of the sixth class. Class Frequency Class Frequency 6-14 6 6-14 6 15-23 4 15-23 4 24-32 6 24-32 6 33-41 8 33-41 8 42-50 7 42-50 7 51-59 5 51-59 5
Math 105 Exam #3
Answer: 42-47 12. Use the following frequency distribution to 12. Use the following frequency distribution to determine the class limits of the next class if an determine the class limits of the next class if an additional class were to be added. additional class were to be added. Class Frequency Class Frequency 6-11 6 6-11 6 12-17 4 12-17 4 18-23 6 18-23 6 24-29 8 24-29 8 30-35 7 30-35 7 36-41 8 36-41 8
Math 105 Exam #3
Answer: 13. Use the following data to construct a Class Frequency frequency table with the indicated class width. 36-37 3 36 37 37 38 41 38-39 1 41 41 42 42 42 40-41 3 42 43 43 44 44 42-43 6 First Class = 36-37 44-45 2 13. Use the following data to construct a frequency table with the indicated class width. 36 37 37 38 41 41 41 42 42 42 42 43 43 44 44 First Class = 36-37 Math 105 Class Frequency Exam #3
Answer: 14. Construct a histogram of the given frequency distribution. The frequency distribution indicates the height in feet of persons in a group of 270 people. Height (feet) Number of Persons 4-5 30 5-6 170 6-7 60 7-8 10
14. Construct a histogram of the given frequency distribution. The frequency distribution indicates the height in feet of persons in a group of 270 people. Height (feet) Number of Persons Math 105 4-5 30 Exam #3 5-6 170 6-7 60 7-8 10 Answer: 15. Construct a frequency polygon. Life of bulb (in hours) Number of bulbs 400-499 45 500-599 80 600-699 120 700-799 70 800-899 35
15. Construct a frequency polygon. Math 105 Life of bulb (in hours) Number of bulbs Exam #3 400-499 45 500-599 80 600-699 120 700-799 70 800-899 35 Answer: 47 16. How many people were surveyed? 16. How many people were surveyed?
Math 105 Exam #3 Answer: 10 17. How many calls were on hold for 4 minutes or 17. How many calls were on hold for 4 minutes or less? less? On-hold Time for Selected Calls to Bryant On-hold Time for Selected Calls to Bryant Lumber Company Lumber Company
Math 105 Exam #3 Answer: 18. Construct a stem-and-leaf display for the 1 0 6 0 3 given data table. 2 0 1 4 10 32 63 16 63 20 3 2 4 9 49 21 34 24 49 10 4 9 9 0 5 5 2 0 55 40 52 39 50 13 6 3 3 18. Construct a stem-and-leaf display for the given data table. 10 32 63 16 63 20 49 21 34 24 49 10 55 40 52 39 50 13 Math 105 Exam #3
Answer: 2.0115 g 19. In his chemistry lab, Harrison measured the 19. In his chemistry lab, Harrison measured the mass of a sample of calcium carbonate six mass of a sample of calcium carbonate six different times. The mass measurements he different times. The mass measurements he observed were 2.016 g, 2.009 g, 2.017 g, 2.011 observed were 2.016 g, 2.009 g, 2.017 g, 2.011 g, 2.012 g, and 2.011 g. Find the median of g, 2.012 g, and 2.011 g. Find the median of these measurements. these measurements.
Math 105 Exam #3
Answer: 249.5 lb 20. The weight in pounds of ten randomly- 20. The weight in pounds of ten randomly- selected football players are: selected football players are: 245 304 310 251 195 245 304 310 251 195 185 230 264 315 196 185 230 264 315 196 Find the mean of these weights. Find the mean of these weights.
Math 105 Exam #3
Answer: $1.76 and $1.85 21. The price in dollars of a gallon of gasoline at 21. The price in dollars of a gallon of gasoline at the end of each month is recorded for one year. the end of each month is recorded for one year. The results are: The results are: 1.19 1.28 1.55 1.76 1.19 1.28 1.55 1.76 1.85 1.85 1.83 1.76 1.85 1.85 1.83 1.76 1.66 1.52 1.48 1.47 1.66 1.52 1.48 1.47 Find the mode of these prices. Find the mode of these prices.
Math 105 Exam #3
Answer: 35.8 milliion 22. The table below gives the total spectator 22. The table below gives the total spectator attendance for various U.S. sports in 1997. attendance for various U.S. sports in 1997. Sport Attendance (millions) Sport Attendance (millions) Pro Baseball 64.9 Pro Baseball 64.9 College Basketball (Men’s) 27.7 College Basketball (Men’s) 27.7 College Basketball (Women’s) 6.7 College Basketball (Women’s) 6.7 Pro Basketball (Men’s) 21.7 Pro Basketball (Men’s) 21.7 College Football 36.9 College Football 36.9 Pro Football 14.8 Pro Football 14.8 Pro Hockey 17.1 Pro Hockey 17.1 Find the midrange of these attendance Find the midrange of these attendance numbers. numbers.
Math 105 Exam #3
Answer: 72 23. To get a C in history, Nandan must average 23. To get a C in history, Nandan must average 70 on four tests. Scores on the first three tests 70 on four tests. Scores on the first three tests were 69, 79, and 60. What is the lowest score were 69, 79, and 60. What is the lowest score that Nandan can get on the last test and still that Nandan can get on the last test and still receive a C? receive a C?
Math 105 Exam #3
Answer: 17 24. Find the range for the set of data given. 24. Find the range for the set of data given. 5 20 3 13 10 5 20 3 13 10
Math 105 Exam #3
Answer: range = $275; standard deviation = $116.17 25. Find the range and the standard deviation of 25. Find the range and the standard deviation of the following prices of notebook computers: the following prices of notebook computers: $1189, $1349, $1450, $1398, $1175, $1229 $1189, $1349, $1450, $1398, $1175, $1229
Math 105 Exam #3
Answer: range = 0.014 V; standard deviation = 0.0052 V 26. Find the range and the standard deviation of 26. Find the range and the standard deviation of the following voltages (in volts) of a sample of the following voltages (in volts) of a sample of watch batteries: 1.212, 1.199, 1.201, 1.202, watch batteries: 1.212, 1.199, 1.201, 1.202, 1.199, 1.198 1.199, 1.198
Math 105 Exam #3
Answer: 0.499 27. Find the area under the normal curve for 27. Find the area under the normal curve for the condition: Find the percent of the area the condition: Find the percent of the area between the mean and 3.01 deviations from the between the mean and 3.01 deviations from the mean. mean.
Math 105 Exam #3
Answer: 7.7% 28. Find the area under the normal curve for 28. Find the area under the normal curve for the condition: Find the area between z =1.41 the condition: Find the area between z =1.41 and z = 2.83 and z = 2.83
Math 105 Exam #3
Answer: 43.5% 29. Find the area under the normal curve for 29. Find the area under the normal curve for the condition: Find the area between z = -2.36 the condition: Find the area between z = -2.36 and z = -0.14 and z = -0.14
Math 105 Exam #3
Answer: 30. 50% 31. 46% 32. 63.7% 33. 97.1% A company installs 5000 light bulbs, each with A company installs 5000 light bulbs, each with an average life of 500 hours, standard deviation an average life of 500 hours, standard deviation of 100 hours, and distribution approximated by a of 100 hours, and distribution approximated by a normal curve. Find the percentage of bulbs that normal curve. Find the percentage of bulbs that can be expected to last the period of time. can be expected to last the period of time. 30. at least 500 hours 30. at least 500 hours 31. between 500 hours and 675 hours 32. between 290 hours and 540 hours 31. between 500 hours and 675 hours 33. less than 690 hours 32. between 290 hours and 540 hours 33. less than 690 hours
Math 105 Exam #3
Answer: No 34. Assume that a sample of bivariate data 34. Assume that a sample of bivariate data yields the correlation coefficient, r, indicated. yields the correlation coefficient, r, indicated. Use the critical values table for the specified Use the critical values table for the specified sample size and level of significance to sample size and level of significance to determine whether a linear correlation exists. determine whether a linear correlation exists. r=0.223 when n = 5 and a = 0.05 r=0.223 when n = 5 and a = 0.05
Math 105 Exam #3
Answer: y= 3.0 x 35. Find the equation of the line of best fit from 35. Find the equation of the line of best fit from the data in the table. Round the slope and the the data in the table. Round the slope and the y-intercept to the nearest hundredth. y-intercept to the nearest hundredth. x 2 4 5 6 x 2 4 5 6 y 7 11 13 20 y 7 11 13 20
Math 105 Exam #3
Answer: y=0.53 x + 4.88 36. Find the equation of the line of best fit from 36. Find the equation of the line of best fit from the data in the table. Round the slope and the the data in the table. Round the slope and the y-intercept to the nearest hundredth. y-intercept to the nearest hundredth. x 0 3 4 5 12 x 0 3 4 5 12 y 8 2 6 9 12 y 8 2 6 9 12
Math 105 Exam #3