00:01
So in this case, our random variable x is binomial with the number of trials is 10, so n is 10.
00:08
That is just our sample size given the problem, and our probability of success is 0 .52, where we define success as a teenager studying at least once a week.
00:20
That is our definition of success.
00:22
So we have to compute the probability that less than half of the students of our sample size, 10, studied.
00:30
So that translates to the probability that x is less than 5.
00:39
Because we are looking for the instance where less than half the students, so less than 5 of the students studied, so x has to be less than 5.
00:51
So that is equal to probability that x is less than or equal to 4, and that is the probability that x is equal to 4, and that is the probability that x is equal to 0 plus x x is equal to 1 plus x is equal to, oops, x is equal to, 2, 3, and 4.
01:28
Then for each of these, we can use the formula up here to calculate each of them, and we can sum them up to get the final answer.
01:38
So let's start with the first one.
01:39
So it's a combination of n choose x.
01:44
So in that case, it is 10 choose 0.
01:48
And probably of success, 0 .52, raise the power of 0 .0...