We look at ways to count numbers that change unpredictably as e.g. in surveys.

Through counting we can set up a table accounting for the frequency of the different numbers.

From this we can calculate the average level and the average change.

The average level can then be used as the winning probability p in a game that is repeated n times.

By counting the different possibilities it turns out that there is a 95% probability that future numbers lie within an interval determined by the average level and change.

Q: How can we count possibilities?

A: By using the numbers in Pascal’s triangle

Q: How can we predict unpredictable numbers?

A: We ‘post-dict’ that the average number is 8.2 with the deviation 2.3.

We ‘pre-dict’ that the next number, with 95% probability, will fall in the confidence interval 8.2 ± 4.6 (average ± 2*deviation)

COUNT2 StudyUnit