00:01
In this problem, first we need to find out the probability that the number of success is equal to 9.
00:09
So, first we know that the population proportion of success is equivalent to 0 .4.
00:15
So, we can find out q that is 1 minus p which is equivalent to 1 minus 0 .4.
00:20
Hence, we obtain 0 .6.
00:21
The sample size n is equivalent to 20.
00:24
Now, we need to find out the probability that the number of successes is equivalent to 9.
00:28
So, in order to find that we could write this as 20 times 0 .4 raised to the power of 9 times 0 .6 raised to the power of 20 minus 9.
00:40
So, we could simplify this and write it as 20 times 0 .4 raised to the power of 9 times 0 .6 raised to the power of 11.
00:49
So, when we evaluate 0 .159738478.
00:56
So, we could approximately write this as 0 .1597 which means that the probability that we were looking for that is the number of successes is equivalent to 9 is equal to 0 .1597.
01:09
So, this is the first part of the answer of the question.
01:13
Now, let us move on to the probability that the number of successes is fewer than 7.
01:20
That is, we could write this as probability of x less than 7...