Statistical sampling

What you'll learn

1. 1

   Imagine you want to know the average height of everyone in your school. You can't measure all 1000 students – too slow!

2. 2

   Why do we use a sample instead of measuring everyone?

3. 3

   Here's a big bag of 100 coloured sweets 🍬🍬🍬. You want to know: what's the most common colour?

4. 4

   Let's sample the sweets together:

5. 5

   Now you try! This box has 50 marbles. Grab a sample of 10 and count how many are blue.

6. 6

   Your sample of 10 marbles has 3 blue ones. What's your best guess for the number of blue marbles in the whole box of 50?

7. 7

   A good sample should be...