Random Samples to Describe Populations

There are 30 people. 11 are picked to take a survey. What is the sample?

• All 30 people

• The 11 people who take the survey

• The 19 people who do not take the survey

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

• Random sample.

• Biased sample.

You want to study a random sample of 4 out of 26 students in your class. Describe a process you could use to create a random sample with 4 subjects.

• Assign each student a number in alphabetical​ order, then select 4 random numbers.

• Select 4 students who sit close to you.

• Select the 4 students whose names come first alphabetically.

• Assign each student a​ number, then select students 1 through 4.

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

• True

• False

Select all that apply!

• A

• B

• C

• D

• E

• Sample A

• Sample B

• Sample C

Identify the Sample: The Huddle House wants to know if their customers buy dessert when they eat out. As people leave the restaurant one evening, 20 people are surveyed at random. Eight people say they usually order dessert when they eat out. The manager at Huddle House concluded that most customers do not order dessert. What is the SAMPLE in this scenario?

• 20 customers from Huddle House

• All customers from Huddle House that evening

• 8 customers from Huddle House

• The employees from Huddle House

At a middle school, the 7th graders will conduct a survey for where to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the student council to choose a location

You want to select a sample from all students at your school. Which of the following selection methods would be considered random?

• Select your five best friends in each grade

• Using a random number generator and a roster, select 50 seventh grade students.

• Select students at school whose last name begins with the letter D.

• Place all students' names in a bowl, and draw 30 names.

Why is it important that samples from populations be random?

• So we can trust the data collected and make inferences about the population

• So Mrs. Dever doesn't get upset

• So we can quickly select the sample and save time

• So we can use technology