Sampling and Surveys

Allison wants to find out how many text messages 7^th graders send a day. Which of the following groups is the most representative sample for her to survey?

• 20 random students on bus 37

• 20 random students in the cafeteria

• 60 random students in the cafeteria

• 60 random students on bus 37

Allison wants to find out how many text messages 7^th graders send a day.   On Monday 20 students chose to complete her survey.Which statement best explains why this was NOT a representative sample?

• the sample size is too small    

• the sample size is too large

• the sample included only those people who were customers at the store

• the sample included only those people who chose to complete the survey

Mr. Headrick surveys the first five 7^th graders who completed the Math MAPs test their thoughts about MAPs testing. Which is most likely to cause a bias in his survey?

• the survey included only 2 questions

• the survey was completed after the test

• the survey was given to 7th graders who completed the test

• the survey was given to the first five 7th graders who completed the test

HCMS administration wants to know what students would like as a reward for meeting MAP goals. The student population at the school is 1,136.Which method would provide the most accurate representation of the students' choices?

• Put all students names in a box and choose 48 to interview.

• Ask all the students at first lunch to vote.

• Allow students to come after school to the media center to vote.

• Go to each first period class and choose 2 students to interview.

Ms. Ochoa is the manager of the lunchroom at HCMS. She wants to add a new dessert to the menu. She decided to conduct a survey in order to help her make the decision about what dessert to add.Which of the following sampling techniques should Ms. Ochoa use in order to obtain the most representative sample to survey the students?

• Ms. Ochoa should ask the students who get off the bus in the morning as they are buying breakfast.

• Ms. Ochoa should ask the adults who eat in the cafeteria at lunch.

• Ms. Ochoa should ask one table of students during the last lunch period.

• Ms. Ochoa should ask at least 400 randomly chosen students at lunch over the course of a week.

Gildan, a t-shirt company, made the claim that “Our shirts are more popular among middle school students”.  Which method most strongly supports the validity of this claim?

• Three randomly selected students prefer our t-shirts.

• Students from two different classes wear our t-shirts

• Students from ten randomly selected classes prefer our t-shirt

• One hundred randomly selected parents prefer our t-shirts.

Marco asked 8 seventh graders at his school “What is your favorite number?”.   He asked them to write down the number on the write board.  Their responses are listed below.

4, 12, 16, 8, 6, 8, 15, 11

What inference can Marco make by using this sample?

• All 7^th grade students have favorite numbers greater than 5

• One seventh-grade student will have a favorite number greater than 20

• The mean favorite number of 7^th graders is 12

• More than half of the 7^th graders have favorite number is at least 8