Section 2 · Lecture 06 · Binomial Distribution
Rather than stating the Binomial formula outright, this tool derives it in four steps: list every sequence of successes and failures, count the sequences with exactly k successes, find the probability of any one of them, and combine the two.
Setup
Step 1
Every possible sequence of outcomes
S = success, probability pF = failure, probability 1 − p
Step 2
How many sequences have exactly 2 successes?
Step 3
Pick one arrangement and find its probability
Click a highlighted sequence in Step 1 to select it.
Step 4
Put it together
Complete Steps 2 and 3 first.