Biased and Random Sampling Population

At a middle school, the 7th graders will conduct a survey to decide where they want to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the student council to choose a location

If I wanted to know how many blades of grass are inside the track, which sampling method could I use?

• Have my students count every blade of grass

• Guess

• Divide the grassy area into 1 inch sections, randomly pick several sections to count, average them together and multiply that by the total square inches.

To determine the most popular children’s programs, a television station asks parents to call in and complete a phone survey.

• Biased Sample

• Unbiased Sample

To determine how often people eat out, every tenth person entering a Chinese restaurant is surveyed.

• Biased Sample

• Unbiased Sample

Cassandra and Isabella want to determine the favorite subject of all students in the middle school. So they place every middle school student's name in a bucket and choose 30 to poll.

• Biased

• Random

At Centre Middle School, the 7th graders will conduct a survey to decide where they want to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the Beta Club to choose a location

Ms. Madson wants to know how many students will attend the next 7^th grade after school dance.  She places all the 7^th grade students’ names in a jar and selects 50. Is this random or biased sampling?

• Random

• Biased

For a survey, a company manager assigned a number to each of the company's 500 employees, and put the numbers in a bag. The manager chose 20 numbers and surveyed the employees with those numbers.

• biased

• random

Biased or Unbiased?

Reign wants to determine the most popular brand of cereal in all of Kentucky. So he polls all the houses on his street to get a sample.

• Biased

• Unbiased

Cherokee County Schools randomly selected 230 teachers to find out which technology resource its teachers feel is the most effective. What is the population in this situation?

• 230 Teachers

• All Cherokee County teachers

• All Cedar Bluff teachers

• All Sand Rock and Spring Garden students