Idea 18of 22Builds onThe spinner has no memory
Streaks happen by chance
Does a long run of one colour mean the spinner is broken?
Today you'll discover
- what a long run of fair spins looks like
- how long streaks get
- what the totals still show
Think first40 spins of a fair half-orange spinner
In 40 fair spins, a streak of 5 blues appears. Is the spinner broken?
Decide first, then press Next. Look for runs of the same letter.
Two rows of 20 small boxes, each marked O for orange or B for blue: 40 spins of a fair spinner. Brackets mark the longest runs, 5 B in a row and 4 O in a row; the totals underneath read orange 21, blue 19, out of 40. The last step shows 40 flips of a fair coin with 6 heads in a row.
See the whole ideathe big idea and the key word, in one place
The big idea
Streaks happen by chance in fair spins; over many spins the totals still land close to the theory.
In this run40 fair spins: 5 blues in a row and 4 oranges in a row, yet 21 orange and 19 blue in all.
Easy to get wrongA streak does not mean the next result is owed to the other colour. Each spin is still 1/2.
Key word
- streak
- the same result several times in a row
Ready to use it?
- Decide whether a streak is a sign of an unfair spinner.