Sampling and Inferencing of Populations

Mr. Thrasher wants to know how the students at Cedar Bluff rate the cafeteria. He surveyed the hungry baseball team after practice last week to rate the school cafeteria. Is this a biased sample of the school's population?

• Yes, because it only asked one group of students

• No, the baseball team has the smartest students

• Yes, because it's voluntary survey

• No, the baseball team are good food critics

Identify the Population:

Cherokee County Schools randomly selected 230 teachers to find out which technology resource its teachers feel is the most effective. What is the population in this situation?

• 230 Teachers

• All Cherokee County teachers

• All Cedar Bluff teachers

• All Sand Rock and Spring Garden students

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

Mrs. Connie wants to know the average student’s opinion of the tardy policy at our school. Which group of students should she survey in order to achieve the most accurate-non-biased results?

• 30 students who are often tardy

• 30 students who are rarely tardy

• 30 7th grade students

• 30 randomly selected students from our school

You want to know what is the favorite sport of 7th graders at CB. You ask 7th graders who play a sport to participate to go to the office 5th period to participate in the survey. This is...

• Biased sample

• Random sample

The population describes:

• The group of people, objects or events being surveyed
• a part of the group being surveyed
• the whole world
• the school

At Centre Middle School, the 7th graders will conduct a survey to decide where they want 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 Beta Club to choose a location

You know what a biased sample is. Using that information, what would you say an unbiased sampling is:

• when you choose the group you think will give you the answer you want, accept volunteers or survey by convenience

• when any member of the population is equally likely to be chosen for the sample

Mr. Walls randomly chose ten 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 every teacher is included in the sample

The city of Cedar Bluff has 832 registered voters. The election for mayor has 3 candidates. A telephone poll taken a day before the election of 67 voters that are friends of the candidates shows these results: 30 Smith, 27 Jones, 10 Brown. Name the sampling method used for this survey.

• Convenience Sample

• Random Sample