7.12 Quizizz: Unit 7 Review

Why do we randomly select our samples?

• because it is easier

• reduce bias to better represent the population

• so we don't get the same answers from everyone

Ana wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy

• thirty students who are rarely tardy

• thirty of her friends

• thirty randomly selected students from her school

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

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

Determine if the following study is biased.

Carlos wants to know the favorite sport of people at his school so he asks his baseball team.

• A. Biased

• B. Unbiased

Determine if the following study is biased.

A company makes DVDs and randomly selects 25 from 1500 to test them to see if they work.

• Biased

• Unbiased

Which random sample is more likely it is to represent the population of Twin Rivers Middle School accurately?

• A. Three students that go to Twin Rivers.

• B. Three hundred students that go to Twin Rivers.

Which is an example of a random sample?

• Polling the first 10 people who enter a room

• Asking a survey question to people who call in

• Drawing 10 names from a hat

What would be the best way to collect statistical data about this question? "How many hours do the students in our school study for final exams on their own?"

• Survey

• This is not a statistical question, so you cannot conduct a study

• Experiment

• Observation

This data is normally distributed.  What percent of the data is in the shaded region?

• 68%
• 95%
• 99.7%
• 50%