00:01
When a customer at a furniture store makes a purchase, there is a 15 % chance they bought a bed.
00:06
So probability of buying a bed, given you made a purchase in general, is 0 .15.
00:14
Okay, buying a bed in general, probability of buying a bed, is 0 .042.
00:21
4 .2%.
00:23
We want the probability of no purchase.
00:29
Okay, so we have very little information here.
00:32
Somehow we want to find probability of no purchase.
00:36
We have the probability of purchase somewhere in here, so i'm going to start by trying to find that probability of p.
00:45
And i do know a formula.
00:49
The probability of a given b is equal to the probability of a and b, divided by b.
01:04
So can i apply that to the probability of making a purchase? probability of bed given purchase would be equal to the probability of both bed and purchase divided by probability of a purchase.
01:29
What's the probability of bed and purchase? try and even this all that a bit.
01:42
Well, i have another formula.
01:45
I know that the probability of a and b is a given b times b...