ELI5: Explain Like I'm 5

Binomial probability

Okay kiddo, let's start with a simple game. Imagine you have a bag filled with red and blue marbles. You know exactly how many red and blue marbles there are, so you can figure out the probability of picking a red marble from the bag.

Binomial probability is a way to figure out how likely it is that a certain event will happen multiple times. So, if we were to take out 10 marbles from the bag, we could use binomial probability to figure out the probability of picking a certain number of red marbles.

Let's say we want to know the probability of picking exactly 3 red marbles out of those 10 marbles. We can use a fancy formula to calculate this probability. It involves multiplying the probability of picking a red marble by itself 3 times, multiplying the probability of picking a blue marble by itself 7 times, and then multiplying those two results together.

The formula looks like this: P(X=k) = (n choose k) * p^k * (1-p)^(n-k)

But don't worry too much about the formula right now. The important thing to understand is that binomial probability is a way to figure out how likely it is that a certain event will happen a certain number of times. It's like trying to predict how many home runs a baseball player might hit in a season or how many times you'll roll a 6 on a dice after rolling it 10 times.

Binomial probability can be really helpful in all sorts of fields, from biology to economics to psychology. It's all about figuring out the math behind the number of times something might happen, and that can help us make better predictions and decisions.