Sample Representative Bias Random

Which random sample is more likely it is to represent the population of Republic Middle School accurately?

• Five students of a school.

• Five hundred students of a school.

Identify the type of sampling used:

A teacher splits her classes up by period. She then uses a RNG to select 10 students from each period to participate in a survey.

• Stratified Random Sample

• Systematic Random Sample

• Cluster Random Sample

• Biased Sample

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.
This is a form of:

• Simple Random Sample

• Stratified Random Sample

• Voluntary Response

• Systematic Random Sampling

Why do we randomly select our samples?

• for control

• reduce bias

• so we don't get the same answers from everyone

• to eliminate confounding results

The sample represents the population.

Choose the answer that says "Representative Sample"

• Random Sample

• Biased Sample

• Representative Sample

Which of the following methods would be the best way to get a representative sample of people living in Mineola?

• ask every fifth person walking into Roosevelt Field Mall on a Saturday morning

• ask the members of the Mineola Chamber of Commerce

• ask the fourth graders at Jackson Ave.

• randomly select 50 addresses from a list of all Mineola residences and call those households

Why is a sample of 1000 people better than a sample of 100 people?

• It reduces the margin of error.

• It decreases bias.

• Having more people is always better.

• More people means that our results are more accurate.

Poll on women’s issues interviewed 1025 women randomly selected from the United States. One question was “Many women have better jobs and more opportunities than they did 20 years ago. Do you think women had to give up too much in the process, or not?” Forty-eight percent of women in the sample said “Yes.” Why can't we just say that 48% of women felt they gave up too much?

• Not all samples would result in 48%

• The margin of error might change.

• The confidence interval might change

• This was a biased survey.

This target depicts

• High bias, high variability

• High bias, low variability

• Low bias, low variability

• Low bias, high variability

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected. 

• systematic

• random sample

• convenience

• biased sampling