0:00
Hello.
00:02
So here we've been given a probability of being left -hundred to be 10%.
00:07
We can say 0 .1.
00:09
Have a sample of 10, we want to find a probability that at most 2 at left -hundred.
00:16
So this is going to be a binomial distribution question.
00:20
Let's look at the formula.
00:24
So we have n combination x times p to the x times q to the n minus x.
00:36
So here q is 1 minus p so q is going to be 0 .9 so now we want to find the probability of at most 2 so that's less than or equal to 2 that's the probability of x equals 0 plus x equals 1 plus probability that x equals 2 so let me just back up here so when x is 0 we have 10 combination 0 times 0 .1, s .0 times 0 .9, esplan 10.
01:23
When x is 1, we have 10 combination 1 times 0 .1, explain 2 times 0 .9, exponent 9.
01:35
Plus, when x is 2, we have 10, combination 2 times 0 .1 squared times 0 .9, esplan 8.
01:50
Let's have 0 .9.
01:56
Just a second.
02:01
Let's put a 9 here...