00:01
Here we consider a binomial distribution based on six trials and probability of success, 0 .6.
00:10
And for part a we are asked to construct the binomial probability distribution.
00:15
So generally the probability function for the binomial random variable is given by this formula, where x can be any integer from 0 up to n, in this case n is 6.
00:35
And so for example, for the first probability, it's the probability that x is equal to 0.
00:41
The probability function simplifies to 1 minus p, which is 0 .4, to the exponent n, which is 6.
00:48
And this comes out to a probability of approximately 0 .0041.
01:01
Now this can be a bit tedious to do for all 7 of these probabilities.
01:05
So let's use excel to do this.
01:08
So in excel, if in column a we put all of the values that x can take on from 0 up to 6, and then in column b, we're going to use the binomial distribution function.
01:25
So for the first row, start with an equal sign.
01:27
Binomial distribution function is what we want to select.
01:31
For the number of successes, i select the cell in column a.
01:35
In this case, it happens to be zero.
01:37
And i hit comma.
01:39
The number of trials is 6.
01:41
Probability of success is 0 .6.
01:44
For the cumulative argument, we enter false because we want the probability that x is exactly equal to whatever is in column a.
01:50
And hit enter, and so we get the same result as we calculated for x equals 0.
01:58
Then we can drag this handle down at the bottom right for all possible values of x.
02:04
And then in column b we have all of the probability masses for all possible values of the random variable x...