Idea 10of 22Builds onMore people won't fix it
A sample with the school's mix
How can you tell if a sample is like the whole group?
Today you'll discover
- how to check a sample's mix
- what the court's mix looks like
- what the hat's mix looks like
Think firstSquares ride the bus: 20 of the 60
In the school, 20 of 60 ride the bus. How many of Maya's 10 ride the bus?
Decide first, then press Next. Count the ringed squares, then compare with the whole grid.
The same 60 students; squares ride the bus, circles walk. Maya's 10 at the court are ringed: all squares. At the right, bars compare bus riders: 10 of 10 in her sample, 20 of 60 in the school. Then the hat's 10: 3 bus riders, close to 1 in 3, and an answer close to the school's.
See the whole ideathe big idea and the key word, in one place
The big idea
Check an attribute you know: a representative sample has about the same mix as the population.
Bus riders, out of 10
School: 20 of 60, 1 in 3. The hat's 10: 3 ride the bus. The court's 10: all 10 ride the bus.
Easy to get wrongA sample from one corner can look fine on one attribute and still be lopsided on another. A fair way of choosing protects every attribute at once.
Key word
- attribute
- a feature you can sort people or things by, like how they get to school
Ready to use it?
- Compare a sample's mix with the population's mix.