BIAS &UNBIAS-STATS

• 7 Students in the hallway

• All students in the band

• 50 8th graders at random

• 100 students during the lunch periods.

• The sample is biased because it contains only people at the state park.

• The sample is biased because it contains only people who are environmentally conscious.

• The sample is biased because it contains only people who are outdoor minded.

• The sample is unbiased.

• The sample is unbiased

• The sample is biased because she is surveying only people at the mall.

• The sample is biased because she doesn't know if the people even watch television.

• The sample is biased because she is interested in only their favorite show.

• The sample is unbiased.

• The sample is biased because he asks only people who own cars.

• The sample is biased because he asking people as they enter the dealership.

• The sample is biased because he is asking people at only one car dealership.

• The sample is biased because only smart students were surveyed.

• The sample is biased because only students at the library were surveyed.

• The sample is biased because only book loving students were surveyed.

• The sample is unbiased.

• Survey the 15 girls in his class

• Survey 60 sixth-grade students

• Survey his 3 best friends

• Survey the 13 boys in his math class

A sample is...

• The group of people you survey to collect data

• The entire group of people you want to learn about

• Free food

A biased sample...

• Is valid

• Favors one or more parts of the population over others

• Accurately represents the entire population

Is the survey biased or unbiased?

To represent all students attending a school, the principal surveys the students in one math class.

• Biased

• Unbiased

Is the survey biased or unbiased?

Customers at a music store are surveyed about what they like to do in their free time.

• Biased

• Unbiased