Random Samples to Describe Populations

You want to estimate the number of students in a high school who ride the school bus. Which sample is best?

• 4 students in the hallway

• All students in the marching band

• 50 seniors at random

• 100 students at random during lunch

Are all quarters in circulation the sample or the population?

• Sample

• Population

Choose the best sample.

• Sample A

• Sample B

Choose the best sample.

• Sample A

• Sample B

If there are 1,000 students in your high school and 40 out of 80 students surveyed said they had a part-time job, how many out the 1,000 students would you predict to have a part-time job?

• 400

• 80

• 40

• 500

Ana wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy

• thirty students who are rarely tardy

• thirty of her friends

• thirty randomly selected students from her school

You ask 75 randomly chosen students at a school how many movies they watch each week.Is the sample representative of student movie preferences? Explain.

You ask 75 randomly chosen students at a school how many movies they watch each week.

What percent of students watch one movie per week?

• 28%

• 21%

• 87.5%

• 70%

You ask 75 randomly chosen students at a school how many movies they watch each week. If there are 1200 students in the school, estimate the number of students who watch one movie per week.

• 900

• 210

• 840

• 336

You ask 20 randomly chosen environmental scientists from your state to name their favorite was to eliminate waste. There are 400 environmental scientists in your state. What percent of the sample prefers eliminating waste by recycling?

• 20%

• 10%

• 0.5%

• 1%