(b)A manager at a bus company wants to survey employees about the new uniforms. Which of the following best describes a convenience sample of employees?
The manager forms groups of
9
employees based on the departments the employees are in. Then, she selects all of the employees in
6
randomly chosen groups.
The manager uses a computer program to draw
54
employees at random and selects these employees. Every set of
54
employees is equally likely to be drawn by the computer program.
The manager asks for volunteers and selects every volunteer until
54
employees are selected. She selects the volunteers because these employees are easily accessible.
The manager asks for volunteers and selects every volunteer until 54 employees are selected. She selects the volunteers because these employees are easily accessible.
(c)A consultant wants to ask workers at a factory about the workers' job satisfaction. Which of the following best describes a cluster sample of workers?
The consultant forms groups of
20
workers based on the lengths of time the workers have worked at the factory. Then, he randomly chooses
4
groups and selects all of the workers in these groups.
The consultant forms
4
groups of workers based on the workers' shifts. Then, he selects
20
workers at random from each group.
The consultant takes a list of the workers and selects every
4th
worker until
80
workers are selected.
The consultant forms groups of 20 workers based on the lengths of time the workers have worked at the factory. Then, he randomly chooses 4 groups and selects all of the workers in these groups.
(a)A botanist at a nursery wants to inspect the health of the plants at the nursery. Which of the following best describes a systematic sample of plants?
The botanist assigns each plant a different number. Using a random number table, he draws
90
of those numbers at random. Then, he selects the plants assigned to the drawn numbers. Every set of
90
plants is equally likely to be drawn using the random number table.
The botanist forms
5
groups of plants based on the ages of the plants (in months). Then, he selects
18
plants at random from each group.
The botanist takes a list of the plants and selects every
5th
plant until
90
plants are selected.
The botanist takes a list of the plants and selects every 5th plant until 90 plants are selected.
A chemist at a pharmaceutical company wants to test the quality of a new batch of microscopes. Which of the following best describes a convenience sample of microscopes?
The chemist takes a list of the microscopes and selects every microscope until microscopes are selected.
The microscopes in the first shipment that was received are easily accessible. So, he selects all of the microscopes in this shipment.
The chemist assigns each microscope a different number. Using a random number table, he draws of those numbers at random. Then, he selects the microscopes assigned to the drawn numbers. Every set of microscopes is equally likely to be drawn using the random number table.
The microscopes in the first shipment that was received are easily accessible. So, he selects all of the microscopes in this shipment.
(c)A facilities supervisor at a sports stadium wants to rate the condition of the seats at the stadium. Which of the following best describes a stratified sample of seats?
The supervisor forms groups of seats based on the dates the seats were last replaced. Then, she selects seats at random from each group.
All of the seats in the VIP section are easily accessible. So, the supervisor selects the seats in this section.
The supervisor forms groups of seats based on the sections the seats are in. Then, she selects all of the seats in randomly chosen groups.
The supervisor forms groups of seats based on the sections the seats are in. Then, she selects all of the seats in randomly chosen groups.
(a)A host on a cruise ship wants to collect data on the time passengers spend at various activities on board. Which of the following best describes a random sample of passengers?
The host forms groups of passengers based on the passengers' ages. Then, he randomly chooses groups and selects all of the passengers in these groups.
The host selects the first passengers who board because these passengers are easily accessible.
The host assigns each passenger a different number. Using a random number table, he draws of those numbers at random. Then, he selects the passengers assigned to the drawn numbers. Every set of passengers is equally likely to be drawn using the random number table.