00:01
So we are given that according to the question, researcher claims the 90 % of people are left handed while the mr.
00:13
Reyes has a statistics class with 30 students.
00:20
So what will be the proof that exactly 25 of them are left handed? so let us start with the concept which we are going to use here for this question.
00:33
So since we know the formula of probability, this can be given by the number of required events divided by the total number of outcomes.
00:58
So let me write event also to be there.
01:01
So first of all, we need to find these two quantities so that we can get the required answer for this question.
01:07
So the probability of getting hit on tossing that we can compute it as we want to find that exactly 25 students out of 30 are left handed.
01:22
So for that, we can use the binomial probability formula, which can be given by probability of x is equals to x.
01:30
That will be gives to or rather than x, we say k over here.
01:35
So it should be nc of k p to the power k, one minus p to the power n minus of k, where nck, this can be given by the combination formula of n factorial divided by n minus k factorial multiplied by k factorial.
02:00
Now, according to question and should be close to 30 and the number of success we want that should be the required value of k that is 25 and the probability of happenings is given see 90%.
02:15
So 90 divided by 100 will comes out 0 .9.
02:20
So this will be the required probability here.
02:22
So let us apply the formula.
02:26
So we want probability of x is equals 25 that will be goes to out of 30.
02:32
We want to select 25...