00:02
Hello, this question is related to the binomial distribution.
00:06
Okay, so here we are given that the probability of success of germinating a seed is 0 .9 and sorry, this is p.
00:16
Okay, and q would be 1 minus p.
00:19
It means probability of failure that would be 0 .1.
00:21
And, and here is 25, that 25 sheets are taken at random.
00:28
Okay, so we need to calculate.
00:30
What is the probability that exactly 20 of them would germinate? okay.
00:35
So for probability, for 20 of them would germinate, it would be n, cr, n is 25, cr is 20 into 0 .9 to the power 20 into 0 .1 to the power 5.
00:51
Or n minus r, that would be 5.
00:54
So 25, sorry, 25 c20 into 0 .9 to the power 20 into 0 .1 to the power 5.
01:07
So exactly 20 seeds would germinate, it has a probability of 0 .0 .6 .6.
01:15
This is the probability.
01:16
Okay.
01:17
So in b part, what does it says? it says that what is the probability that 20 or more will germinate.
01:24
So priority of 20 we have already calculated, you will calculate probability of 21, 22, 23, 24 and similarly 20.
01:36
This was 24, 25.
01:39
Okay.
01:41
So i will write formula for 1, then rest of all, i will just directly write the answers.
01:47
So 21, 25, c21, 0 .9 to the power 21 into 0 .1 to the power 1 .1 to the power.
01:55
4 so this would be 25 c 21 into 019 to the power 21 into 0 .1 to the power 4 so it is coming out to be 0 .138 4 so next would be 25 c 22 into 0 .9 to the power 22 into 0 .1 to the power 3 so this would be 0 .2 to 625 again, 25c23 into 0 .9 to the power 23 into 0 .1 to the power.
02:39
So it is coming out to be 0 .2659...