populations and samples
This is the whole group you want to learn about.
What is a population?
You look at a sample to make a guess about a whole group. That guess is called what?
What is an inference?
Group A: 12 of 20 like apples. Group B: 10 of 25 like apples. Which group has more?
What is Group A?
If you flip a coin what is the chance it lands on heads?
What is 1 out of 2? (or what is 50%)
If 1 inch on a map equals 5 miles, how many miles do 3 inches represent?
What is 15 miles?
This is a smaller group taken from a bigger group to ask questions or study.
What is a sample?
You survey 20 students, and 15 say they like pizza. Based on that, you think most students at your school like pizza. What are you doing?
What is making an inference from data?
Group A: 18 of 30 like basketball. Group B: 20 of 50 like basketball. Which group has a higher percent?
What is Group A?
A bag has 3 red and 7 blue marbles. What’s the probability of picking a red marble?
What is 3 out of 10?
A scale drawing shows a car as 4 cm long. The scale is 1 cm = 2 meters. How long is the real car?
What is 8 meters?
You pick 20 students out of the whole school to ask about lunch. What are those 20 students called?
What is a sample?
If 15 out of 20 students like soccer, how many students out of 100 would you expect to like soccer?
What is 75 students?
Group A: 16 of 40 like dogs. Group B: 15 of 30 like dogs. Which group has a higher percent?
What is Group B?
A spinner has 4 equal sections: red, blue, green, and yellow. What’s the chance it lands on green?
What is 1 out of 4?
On a blueprint, 1 inch = 10 feet. If a room is 5 inches long on the blueprint, what is its actual length?
What is 50 feet?
You ask students in the art club what their favorite subject is. You call that group a what?
What is a biased sample?
You survey 80 students, and 56 say they like math. About how many students would that be in a school with 400 students?
What is 280 students?
City A: 24 of 60 like biking. City B: 45 of 90 like biking. Which city has more?
What is City B?
There are 5 green balls, 3 yellow balls, and 2 red balls in a box. What’s the probability of picking a yellow ball?
What is 3 out of 10?
A model airplane is 12 inches long. The scale is 1 inch = 3 feet. What is the real airplane’s length?
What is 36 feet?
You write down every student’s name, mix them up, and pick a few to ask a question. What type of sample is that?
What is a random sample?
A class survey shows that 12 out of 15 students have a pet. If the school has 300 students, about how many might have pets?
About 240 students
School X: 75 of 100 like science. School Y: 81 of 120 like science. Which school has a higher percent?
What is School X?
You roll a 6-sided die twice. What is the probability of rolling a 4 both times?
What is 1 out of 36?
The scale is 1 inch = 20 miles. Two cities are 3.5 inches apart. How far apart are they and how long to drive at 60 mph?
What is 70 miles and 1 hour 10 minutes?