00:01
In this question, we are given that in a pizza ordering, probability of pizza is cheese is 0 .6, and that you ordered nine pizzas.
00:13
I'm going to let x be the number of pizzas out of nine that are cheese.
00:18
Now x actually follows the binomial distribution.
00:21
Let's take the look at how it follows the binomial distribution.
00:25
For the binomial distribution, there are four criteria.
00:29
The first criteria, the number of trial and is fixed and are identical.
00:34
Now in this case, the trials here are we're looking at nine pizzas and for each of these pizza we're just looking at whether it's cheese or not.
00:43
So the trial experiment here is the same.
00:47
So point number one is satisfied.
00:51
Criterion number two, each trial is independent.
00:53
So for this nine pizza, each pizza whether they are cheese or not, is independent of the other pizzas.
00:59
So point two is fulfilled.
01:04
Now third point, each trial results in one and two outcomes, success and failure.
01:09
So for each pizza, the success would be it is a cheese pizza and the failure will be it is not a cheese pizza.
01:16
So point three is fulfilled.
01:19
Now point four, the probability of success in a single trial denoted by p remains the same from trial to trial.
01:26
Now this means that the probability that a pizza is cheese, which is 0 .6 and this is the same for every pizza.
01:35
So 0 .4 is fulfilled...