Sample Size and Population

Carl wants to estimate the number of students in 5 th grade who like to play basketball. He needs to create a random sample of students. How should Carl collect his sample?

• Carl should ask 30 students who are playing basketball.

• Carl should ask 30 5th-grade students.

• Carl should ask 30 students who go to the same school.

• Carl should ask 30 students who are playing football

Which of the following would produce a sample that would be representative of a school's seventh-grade population?

• surveying every fifth seventh grader in a prealgebra class

• surveying every fifth seventh grader in the library

• surveying every fifth seventh grader entering the school at the beginning of the school day

• surveying every fifth seventh grader in the cafeteria in one of the school's three lunch periods

A TV station wants to conduct a survey to determine which sport should be shown on Sunday in the viewing area: a football game or a baseball game. Which of the following samples would be a fair representation of people to ask?

• Sample 1: 50 high school football players and 50 high school baseball players

• Sample 2: 50 boys and 50 girls at the local middle school

• Sample 3: 100 people who were preselected because they do not watch sports

• Sample 4: every 100th person at a local shopping mall

A company wants to provide better customer service to all of their 2000 clients. The company needs to create a sample of clients to survey. How should the company select their sample of clients? Select two that apply.

• Every employee in the company should recommend 1 client to survey.

• The company should have a computer randomly generate a list of 200 clients to survey.

• The company should survey every 5 th client that makes an appointment.

• The company should choose the first 50 clients that volunteer to take the survey.

A representative sample of 50 students were surveyed about what they preferred on the lunch menu at their school. The table below shows their responses.

In a group of 250 students, how many students are expected to prefer pizza? In a group of 250 students, how many students are expected to prefer pizza?

• 60

• 70

• 10

• 95

A restaurant offers three types of meats: chicken, beef, and pork. The waiters surveyed 50 customers at random about their favorite type of meat. The results are listed in the table and on the graph below. If the restaurant orders 400 pieces of meat, how many pieces should be chicken?

• 25

• 100

• 200

• 375

A scientist asked four of his doctor friends if they thought the new Brand X lotion that he developed was effective. Three responded​ "yes." The scientist used the results to write a TV advertisement claiming that "3 out of 4 doctors prefer Brand X lotion​." Is this a valid​ inference? Explain.

• No, because the doctors asked are not a representative sample of the population of doctors.

• Yes, because 3 doctors said yes out of 4 who were asked.

• Yes, because the doctors asked are a representative sample of the population of doctors

• No, because 3 doctors said yes out of 7 who were asked.

Out of a group of 30 volunteers,13 people are chosen to participate in a survey about the number miles they drive to work each week. What is the sample in this​ situation?

• The 13 people selected to participate

• The people conducting the survey

• The 17 people not selected to participate

• The 30 volunteers

A group of students is studying the number of people who like music in their school. They surveyed everyone in their school. One of the students incorrectly said that the people they surveyed represents a sample because it only includes the people in their school. Identify the population.

• Everyone in their school who likes music

• Everyone in all schools

• Everyone in their school

• Everyone who likes music

The dot plot below shows the weights of Dr. Smith's 12–year–old patients.

What is the difference between the mean weights of the boys and girls?

• 1 lb

• 6 lbs

• 10 lbs

• 9 lbs