a)A botanist at a nursery wants to inspect the health of the plants at the nursery. Which of the following best describes arandom sampleof plants?

The botanist forms groups of8

plants based on the heights of the plants. Then, he randomly chooses9

groups and selects all of the plants in these groups.

All of the plants that are in one particular room at the nursery are easily accessible. So, the botanist selects the72

plants in this particular room.

The botanist assigns each plant a different number. Using a random number table, he draws72

of those numbers at random. Then, he selects the plants assigned to the drawn numbers. Every set of72

plants is equally likely to be drawn using the random number table.

(b)A facilities supervisor at a sports stadium wants to rate the condition of the seats at the stadium. Which of the following best describes astratified sampleof seats?

The supervisor forms6

groups of seats based on the dates the seats were last replaced. Then, she selects13

seats at random from each group.

The supervisor uses a computer program to draw78

seats at random and selects these seats. Every set of78

seats is equally likely to be drawn by the computer program.

The supervisor forms groups of13

seats based on the sections the seats are in. Then, she selects all of the seats in6

randomly chosen groups.

(c)A chemist at a pharmaceutical company wants to test the quality of a new batch of microscopes. Which of the following best describes aconvenience sampleof microscopes?

The chemist takes a list of the microscopes and selects every4

th

microscope until80

microscopes are selected.

The microscopes in the first shipment that was received are easily accessible. So, he selects all80

of the microscopes in this shipment.

The chemist forms4

groups of microscopes based on the prices of the microscopes. Then, he selects20

microscopes at random from each group.