unit 3

Emily wants to find out if the carpool line around her school causes too much traffic on neighborhood roads. Which is a valid sample for her survey?

25 families living near the school

A population of middle school students contains 160 sixth graders, 180 seventh graders, and 140 eighth graders. Nine seventh graders were part of a random sample of the population chosen to participate in a survey. For the sample to accurately represent the population, about how many sixth graders should be chosen?

8

The student government wants to determine the theme for the eighth grade dance. Which group would it be best to take a sample from?

8th graders

A supervisor wants to know the average number of hours worked by employees in a factory. There are 18 managers, 240 laborers, and 54 administrators. Three managers are chosen to participate in the survey. In order for the sample to accurately represent the population, about how many administrators should be chosen?

9

An employer asks the survey question "How much money do you spend on gasoline per week to get to work?" of her employees that drive to work. Which best describes why she chose to only ask the employees that drive to work rather than all of her employees?

The employees that drive to work were the target of her survey.

Kristin wants to ask the managers of the fast food restaurants in a large city "How do you retain employees?" What condition must be true to justify surveying only a sample of the managers instead of surveying the entire population of managers?

The population is expensive and time-consuming to survey.

Amalie wants to know if students in her class prefer hot dogs or hamburgers. Why should Amalie survey the entire population rather than a sample of the population?

The population is small enough to survey the entire group.

Traverion wants to find the answer to the question "How much money does the average college professor make?" He surveys 50 professors from the university in his hometown. Which best describes whether or not the results of his survey would represent the responses from the entire population of college professors?

The results do not represent the population because the sample does not represent professors from different areas.

A landscaper wants to find the answer to the question "How much time do people in Raleigh, North Carolina, spend doing yard work in one week?" He asks the owners of all 120 houses in a Raleigh neighborhood. Which best describes the accuracy of the results of the survey?

The survey results will be inaccurate because lawns in one neighborhood do not represent all types of lawns in a large city.

A student wants to find the answer to the question "What is the most popular restaurant in Bedford?" He asks 20 randomly selected customers at one local restaurant. Which best describes the accuracy of the results of the survey?

The survey results will be inaccurate since the entire sample of the population was eating at the same restaurant.

Residents in a neighborhood determine the approximate number of dandelions in each yard. Then, they treat some yards with a weed-killing substance. The residents want to answer the question "About how many dandelions are in your yard?" to determine the effectiveness of the weed killer. From which group would it be best to take a sample?

all residents of the neighborhood

A middle school contains sixth, seventh, and eighth graders. Each grade level contains approximately the same number of students. The principal wants to find the answer to a survey question affecting each student in the school. He asks a sample group "What time do you get up in the morning?" Which of these characteristics define the best sample?

an equal number of students chosen at random from each grade level

Scientists are studying hurricanes to determine the number of hurricanes in the past 50 years that have caused greater than $1 million in damages. Which best describes the population?

hurricanes

A teacher needs to find out how many seventh graders will be going on a field trip. Which best describes the population that the teacher should survey?

the parents of the seventh grade students

Biologists are studying tropical plants to determine how far north each type of plant can survive. What is the population?

tropical plants

When is choosing a sample from a population least likely to be appropriate? Choose all that apply.

when the population is small when the sample contains proportions of items/events/people that are different from those of the population