00:01
A drug is 75 % effective and we have 12 patients being treated.
00:06
So the probability of each of them having an effect from the drug is 75%, 0 .75.
00:12
We want the probability it is effective for at least 9 of them.
00:18
So i'll have x, the number it is effective for, out of 12, and we want that to be at least 9.
00:23
Looking at this i see a binomial distribution.
00:27
We have 12 independent trials, they're not going to influence each other.
00:31
Two outcomes, it's effective for them or it isn't.
00:34
Same probability p for each.
00:37
To solve a binomial question you have three main choices.
00:40
You could use the binomial formula, you could use the tables in the back of your textbook, or you could use technology.
00:48
I'm going to use excel with the binomdist function.
00:54
There are similar functions on any statistical software you like or your calculator.
01:00
This has four inputs...