Ch. 3 Intro Statistics Review

1. A sample in which every person, object, or event has an equal chance of being selected.

• A. Random sample.
• B. Biased sample.

_______ is the entire group of objects or individuals considered for a survey.

• Sample
• Population
• Random Sample
• Quartile

A state fair had 1,019,887 people in attendance. The fair committee performed a survey. The question was, “What do fairgoers enjoy most about the fair?” Of those who responded, 83% reported eating traditional foods. Which group of people represents the sample group?

• Fair goers who like traditional foods
• The fair committee
• Fair goers who responded to the survey
• All fair goers

Elise, a supermarket employee, approached 50 random customers and asked whether they would be willing to discuss what they like most about the store. She interviewed the 22 who said yes. Is this sample of the supermarket's customers likely to be biased?

• yes

• no

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

A school randomly chose ten English teachers and asked them which type of juice their students would prefer. Which reason best shows why this sample is biased?

• The sample didn't include students.
• The sample is too small.
• The sample can only be accurate if each teacher is included in the sample

Is the following question biased? Why or why not?

"To see who has a computer at home, the front office asks 10 randomly chosen students from each grade."

• Yes, because it favors the responses from one grade over the others

• Yes, because it is a random sample.

• No, because it is a random sample.

• No, because most students have computers.

Which scenario would produce the least biased results?

• asking athletes at a gym what their favorite television show is

• asking fans at a baseball game who their favorite baseball team is

• asking shoppers at a store where their favorite place to shop is

• asking students in a college library what their favorite college sports team is

A factory manufactures light bulbs. The factory currently has 300 boxes of light bulbs in its warehouse. To test the quality of bulbs, Alex decides to take out a sample of bulbs and test them to see if they work. Which surveying method will give him the LEAST valid results?

• selecting ten boxes randomly, mixing the bulbs of these boxes together and then selecting ten bulbs randomly

• selecting ten boxes randomly and then selecting one bulb randomly from each box

• selecting one bulb randomly from every tenth box

• selecting one box randomly and then selecting all the bulbs from the box

True or False: all samples lead to a good prediction about an entire population.

• True
• False