Make Predictions and Biased Unbiased Samples

A school surveys all 7th grade boys to determine what to sell in the school store.  This sample is _________.

• Biased

• Unbiased

• Representative

• Peanut butter cups

The table shows the results of a school survey about favorite frozen yogurt flavors. If there are 432 students in the school, predict how many would select vanilla or strawberry as their favorite flavor.

• 72 students

• 126 students

• 198 students

• 942 students

A principal randomly chooses 40 students from grade 5. Of these students, 9 were wearing watches. Based on this information, what is the most reasonable prediction of the number of students wearing watches in a group of 120 students?

• 27

• 9

• 18

• 80

Making a prediction in statistics is a

• random guess

• 100% accurate fact

• using a magic 8 ball

• using previous information to determine how likely something is to happen

The sample should REPRESENT the population so you can INFER what the larger group is like.

If you take a BAD sample, it does not allow you to make inferences about the larger population.

Choose the option below that says "Biased Sample"

• A sample that accurately represents the population

• A sample that is selected randomly from the population

• Biased Sample

Shelley wants to survey grocery shoppers about their favorite brands. She goes to the store at 8am and surveys the first 50 people. Is this a biased sample or unbiased sample?

• Biased Sample

• Unbiased Sample

Casey surveyed the members of his soccer team to ask them what their favorite sport is. Is this a biased sample or unbiased sample?

• Biased Sample

• Unbiased Sample

The table shows the results of a survey of 200 people attending a hockey game.
The attendance for the hockey game is about 25,000 visitors each game.  Based on the table, how many people out of 25,000 could be expected to buy a pennant?

• 1,375

• 1,650

• 2,750

• 3,850

A newspaper randomly chooses 100 names from its subscriber list and then surveys those subscribers to find out if they read the sports section. This sample is ........

• unbiased

• biased

Biased or Random?

Chloe and Danna 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 sample

• Random sample