For each of the following, identify the sample and population scores:
a. A social psychologist interested in drinking behavior investigates the number of drinks served in bars in a particular city on a Friday during "happy hour." In the city, there are 213 bars. There are too many bars to monitor all of them, so she selects 20 and records the number of drinks served in them. The following are the data:
|
50
|
82
|
47
|
65
|
|
40
|
76
|
61
|
72
|
|
35
|
43
|
65
|
76
|
|
63
|
66
|
83
|
82
|
|
57
|
72
|
71
|
58
|
| Social |
b. To make a profit from a restaurant that specializes in low-cost quarter-pound hamburgers, it is necessary that each hamburger served weigh very close to 0.25 pound. Accordingly, the manager of the restaurant is interested in the variability among the weights of the hamburgers served each day. On a particular day, there are 450 hamburgers served. It would take too much time to weigh all 450, so the manager decides instead to weigh just 15. The following weights in pounds were obtained:
|
0.25
|
0.27
|
025
|
|
0.26
|
0.35
|
0.27
|
|
0.22
|
0.32
|
0.38
|
|
0.29
|
0.22
|
0.28
|
|
0.27
|
0.40
|
0.31
|
| Other |
c. A machine that cuts steel blanks (used for making bolts) to their proper length is suspected of being unreliable.The shop supervisor decides to check the output of the machine. On the day of checking, the machine is set to produce 2-centimeter blanks.The acceptable tolerance is ±0.05 centimeter. It would take too much time to measure all 600 blanks produced in 1 day, so a representative group of 25 is selected. The following lengths in centimeters were obtained:
|
2.01
|
1.99
|
2.05
|
1.94
|
2.05
|
|
2.01
|
2.02
|
2.04
|
1.93
|
1.95
|
|
2.03
|
1.97
|
2.00
|
1.98
|
1.96
|
|
2.05
|
1.96
|
2.00
|
2.01
|
1.99
|
|
1.98
|
1.95
|
1.97
|
2.04
|
2.02
|
| I/O |
d. A physiological psychologist, working at Tacoma University, is interested in the resting, diastolic heart rates of all the female students attending the university. She randomly samples 30 females from the student body and records the following diastolic heart rates while the students are lying on a cot. Scores are in beats/min.
|
62
|
85
|
92
|
85
|
88
|
71
|
|
73
|
82
|
84
|
89
|
93
|
75
|
|
81
|
72
|
97
|
78
|
90
|
87
|
|
78
|
74
|
61
|
66
|
83
|
68
|
|
67
|
83
|
75
|
70
|
86
|
72
|
| Biological |