Statistics Basics

Statistics Basics

You will be able to describe statistics as a way to gain information about a population by examining a sample of the population

​Key Terms for this Unit

population - the group of people

​data - the information collected from the survey or experiment

sample - a small section of the population

What is the population?


What is the sample?


What is the data?

​Imagine the mayor of Oshkosh wants to know how many people want a new park put in by the lake. They conduct a survey outside of city hall and end up asking 120 people and get their opinion.

population - the group of people

​data - the information collected from the survey or experiment

sample - a small section of the population

What is the population?




What is the sample?




What is the data?

Carly is bringing in snacks for her whole girl scout troop and wants to know what to bring, but she wasn't sure. She decided to ask 6 of her friends and they said chips and queso.

Multiple Choice

A grocery store manager wants to know how much people spend at Festival Foods. He decides to ask the next 70 people that come in and find out that they spend $52 a piece on average.

What is the sample in this situation?

• Everyone who shops at Festival Foods

• 70 People

• $52.00

• The store manager

Multiple Choice

A grocery store manager wants to know how much people spend at Festival Foods. He decides to ask the next 70 people that come in and find out that they spend $52 a piece on average.

What is the population in this situation?

• Everyone who shops at Festival Foods

• 70 People

• $52.00

• The store manager

Multiple Choice

A grocery store manager wants to know how much people spend at Festival Foods. He decides to ask the next 70 people that come in and find out that they spend $52 a piece on average.

What is the data in this situation?

• Everyone who shops at Festival Foods

• 70 People

• $52.00

• The store manager

Multiple Choice

North Carolina is electing its next Senator. They want to know who people are voting for, so they survey 5,000 people. They find that 54% of people are voting for Candidate A.

What is the population in this situation?

• Everyone who can vote in North Carolina

• The 5,000 people surveyed

• 54% of people are voting for candidate A

• The Senator who is getting elected

Multiple Choice

North Carolina is electing its next Senator. They want to know who people are voting for, so they survey 5,000 people. They find that 54% of people are voting for Candidate A.

What is the data in this situation?

• Everyone who can vote in North Carolina

• The 5,000 people surveyed

• 54% of people are voting for candidate A

• The Senator who is getting elected

Multiple Choice

North Carolina is electing its next Senator. They want to know who people are voting for, so they survey 5,000 people. They find that 54% of people are voting for Candidate A.

What is the sample in this situation?

• Everyone who can vote in North Carolina

• The 5,000 people surveyed

• 54% of people are voting for candidate A

• The Senator who is getting elected

Draw

A shoe factory wants to make sure that their shoes are up to their quality standards, so they pull off and check 10 every day of the 2,000 shoes they make. They record how many have any problems with them.

What is the population and what is the sample in this situation?

Draw

The people who manage the Green Bay Packers wanted to see how people felt about the food at the game. They surveyed 500 people outside the stadium before their game against the Cowboys.

What is the population and what is the sample in this situation?

representative - a typical member of a population

generalization - a broad statement applied to a group

What problems can you think of from making a generalization about a group based on one person?

Imagine you ask your classmates how many pets they have. You ask all 27 students and find that 15 have two pets, 5 have one pet, 4 have zero pets, 2 have three pets and 1 has 8 pets.

You wanted to describe what a 'typical' member of the survey is and say that they have 1 pet on average. Do you think this is a good description of the population?

A school counselor needs to know what is the main motivation for students getting good grades in high school. They decide to ask 40 seniors (20 boys and 20 girls). Do you think that this would be a good representation of every student in the school?

An office manager at a local computer company wants to see how workers feel about the new parking. They decide to ask the first 15 people that walk into the office that day. Do you think that this would be a good representation of everyone in the office?

Open Ended

A wrestling coach wanted to see how many push-ups his wrestlers could do on average. He decided to record each wrestlers number of pushups and then just picked out 10 of the 58 at random and determines that his wrestlers can do around twenty on average.

Do you think this is a good representation of all his wrestlers? (Include 'yes' or 'no' and why)

Open Ended

A researcher wants to know what the average age of someone who retires in the United States. They look at all the states in the south and determine the average retirement age is 58.

Do you think this is a good representation of all the people who retire in the USA? (Include 'yes' or 'no' and why)

Open Ended

A fisherman wants to know what type of fish are in Lake Pullman. They go out fishing in the morning on Monday, Tuesday, Thursday, Friday and Sunday for two weeks in the summer and record all the fish they catch.

Do you think this is a good representation of all the fish in the lake? (Include 'yes' or 'no' and why)

Open Ended

In the 1948 election, a newspaper in Chicago wanted to predict who would win the election. They mainly called people on the phone to ask who they were voting for. (Keep in mind that in 1948, only more wealthy people had telephones)

Do you think this is a good representation of all the people voting in the 1948 election? (Include 'yes' or 'no' and why)

​At the time, telephone surveys were the dominant method of public polling. While this system was simple and cost-efficient, it failed to accurately represent the population since, unlike modern day, owning a telephone in the 1940s was a luxury.

Therefore, the random samples overrepresented wealthier households at the expense of lower-income and/or rural households.

This ended up being a very inaccurate sample of what the voting citizens in the United States were thinking.

What could they have done differently?

​The Election of 1948 and 'Random' Surveys