00:01
In this question, we're given that 60 % of people browsing at kremus bookmark will make a purchase, and 10 people are browsing in a store.
00:09
I'm going to let x with the number of people out of 10 in the store who will make a purchase.
00:14
Now, x follows a binomial distribution.
00:17
N is 10, and p the probability of success.
00:20
In this case, probability of a person making a purchase is 60 % or 0 .6 in decimal.
00:27
So probability of x equals to r will be 10 choose r.
00:32
0 .6 to power r, and 1 minus 0 .6 is 0 .4 to the power of 10 minus r.
00:39
So probability at least 7 will make a purchase.
00:42
So this we are looking at probability of x greater equals to 7.
00:47
Now we'll split it into a few mutually exclusive case...