00:01
For this problem to begin, we know that x is a binomial random variable, where the number of trials n is equal to 5, the probability of success on an individual trial, p, is equal to 0 .2.
00:21
And we want to find the probability that x is between 2 and 4.
00:31
To do that, we can note that for any binomial random variable, we know the probability of getting k successes out of n trials.
00:41
Where the probability of success is p, it's given by n -chus k times p to the power of k, times 1 -p -p to the power of n -m minus k.
00:57
So, to find probability of x between 2 -4 -inclusive, all we need to do is calculate that out, or calculate probability x equals 2, 3, and 4, and add together the values...