Intro to Statistics

Populations, Samples, and Generalizing from a Sample

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Today, we will...

• learn about collecting data from a sample that is selected from a population

• what can be learned about the population by looking at a sample from that population

Multiple Choice

A ______ is the entire set of objects from which data might be collected

• sample

• population

• numerical summary

• statistic

Multiple Choice

A _______ is a subset of the population.

• population

• numerical value

• statistic

• sample

Multiple Choice

True or False: All samples lead to a good prediction about the entire population.

• True

• False

Multiple Choice

A student wants to know which type of of pizza high school students perfer. Which of the following options is a good, representative sample of the population?

• Asking all the 10th graders in the school

• Asking 20 students from each grade level

• Asking the school principal which type of pizza he perfers

• Asking the students who walk to school

Multiple Choice

A beverage company wants to see if people in the United States like their new logo. Which of the following represents the population?

• 2,000 people ages 5-13

• A selection of logo artists

• A selection of shoppers from different states

• all the people in the United States

Multiple Choice

A beverage company wants to see if people in the United States like their new logo. Which of the following represents the best choice for a sample?

• a collection of shoppers from different states

• all the people living in the United States

• a selection of logo artists

• 2,000 children from ages 5-13

Multiple Choice

Which of the following is NOT a reason why random samples are preferred over surveying the entire population.

• A random sample allows you to survey whoever you want.

• Surveying the entire population may cost too much money.

• Surveying the entire population takes too much time.

• Surveying the entire population can be a challenge because not everyone may respond.

Multiple Choice

Which of the following situations would you want to collect a sample rather than surveying the entire population?

• the median price of homes in Ohio

• how many students in the class like mushrooms on their pizza

• how many students have more than one pet

• the typical number of home runs for each player on the baseball team

Multiple Choice

A toy store owner wants to know how much kids spend each month on toys. Which choice is the best representation of the population?

• 220 wealthy kids

• all the kids who buy toys

• 100 boys ages 8-12

• 125 girls ages 10-15

Multiple Choice

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?

• 30 of her friends

• 30 randomly selected students in the school

• 30 students who are often tardy

• 30 students who are not often tardy

Multiple Choice

A survey company was trying to see if people in a state thought the pollution was too high. Which choice BEST represents the population to be surveyed?

• a selection of people who live in small towns

• a selection of people who live in clean neighborhoods

• a selection of people from each city in the state

• all the people in the state

Multiple Choice

A school principal wants to see which subject the 695 students in his school liked best. Which choice BEST represents a representative sample?

• all the girls in the school

• the students who have an A in math class

• the students who have a D in science class

• 1 classroom for each grade level

Multiple Choice

True or False: You want to see how many students take the bus home from school. You go to the bus stop and ask students how they get home everyday. This is a good, representation of the population.

• True

• False

Open Ended

How could you collect data to answer the question, "How many pets do people own in my neighborhood?"

Open Ended

How would you collect data to answer the question, "What percentage of girls and boys in your school have a curfew?"

Census

• when data is collected from an entire population

• The United States conducts a census of its population every 10 years

Open Ended

The United States conducts a census every 10 years. Why do you think the census is important in the United States?

Poll

How do you feel about the difference between population and sample?

• I feel confident and I'm ready to move on

• I almost have it.

• I'm a little confused and have more questions.

• I am lost and need help.

Types of Data​

​Data may be qualitative or quantitative. Once you know the difference between them, you can know how to use them.

​Qualitative data - information about qualities; information that can not actually be measured. For examples: the color of the sky, the softness of the cat, etc.

​Quantitative data - information about quantities; information that can be measured and written down with numbers. For examples: the amount of money in your wallet, your age, etc.

Multiple Choice

Chris asked people at a football game their age. What type of data will he be collecting

• Quantitative

• Qualitative

Multiple Choice

Malyk asked his friends, "what is your favorite food?"

• Quantitative

• Qualitative