The principal at Marina Middle School wants to determine if the 120 students in the seventh grade prefer to visit the aquarium or the science museum for their end-of-year trip. Select all the sets of people that would be a representative (good) sample of the population. (Hint: 2 answers)

• 20 sixth-grade students, 20 seventh-grade students, and 20 eighth-grade students

• 10 seventh-grade boys and 10 seventh-grade girls

• 25 seventh-grade students

• 15 seventh-grade boys and 5 teachers

• 25 students from the school

Students in Mrs. Walsh’s math class wanted to know the favorite snacks of students in the school. How could they generate a random sample to survey?

• The class could obtain an alphabetized list of all of the students in the school and select every seventh student.

• The class could each ask one of their best friends.

• The teacher can choose a sample of students.

• The class could select the first 20 students that visit the school canteen shop.

The food service manager conducted a random survey of students to determine their preference for new lunch menu items. Select all the inferences that can be drawn from the manager’s data. (Hint: There are 3 answers)

• About twice as many students prefer salad bar as compared to pita sandwiches.

• Burritos are the most preferred item.

• About three-fourths of students prefer either salad bar or burritos.

• Twice as many students prefer pizza as compared to pita sandwiches.

• About half as many students prefer pita sandwiches as compared to burritos.

Margo wants to convince her father to change her curfew from 9 P.M. to 10 P.M. She gathers data on curfew times from a random sample of students at her middle school. Can Margo use these data to present a valid inference that will convince her father? Explain.

• No. Most students have a curfew of 9 P.M. or earlier.

• Yes. Most students have a curfew of 10 P.M. or earlier.

• Yes. Some students have a curfew of 10 P.M. or later.

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

• True

• False

What inference can you draw from this survey?

• I can infer that most students in this school like pizza.

• I can infer that very few students like hamburgers.

• I can infer that their favorite is corn dogs.

• I can infer that most students in this school like hamburgers.

A travel club has 3,000 members. A random sample of 50 of the club members found that 12 people like mountain vacations best. Which statement is NOT supported by the sample data?

• Twenty-four percent of those sampled say they like mountain vacations best.

• An estimated 720 club members would likely say they enjoy mountain vacations best.

• Almost one-quarter of club members would likely say they enjoy mountain vacations best.

• More than 2,500 club members would likely say they prefer other vacations over mountain vacations.

How can sample data be used to form an estimate about the population?

• A proportion can be solved to relate the sample to the population.

• A proportion can be solved to relate the sample to the mean.

• A proportion can be solved to relate the sample to the median.

• You cannot make an estimation from sample data.

Russell randomly surveys seventh-graders in his school and finds that 6 of 30 attend summer camp. If there are 200 seventh-graders in his school, about how many are expected to attend summer camp?

Mathematical Equivalence

ON

Group A and Group B were randomly sampled from the same population. What inferences can you make?​ Group B has a higher ​ (a)   and less overall ​ (b)   (​ (c)   range) than Group A.

• median

• variability

• smaller

• bigger

• IQR