00:01
So for your problem, you have quite a few different questions asked here, and i'm going to help you on just a set of them.
00:06
So if we look at number 3, we can see that you have a probability distribution.
00:11
It looks like it is x value of 1, 2, 3, and that the probability of x is equal to 0 .5, 0 .35, and 0 .15.
00:22
So notice that the sum of these probabilities does add up to 1.
00:27
And you want to determine what the mean is and the standard deviation is.
00:33
So that's going to be taking 1 times 0 .5 plus 2 times 0 .35 plus 3 times 0 .15.
00:41
I would also suggest that you go into your calculator and add in 1, 2, and 3 into list 1 and then these probabilities into list 2.
00:53
And then that way it will will allow you to find those values directly.
00:58
So i'm quickly doing that.
00:59
I'm up to putting the probabilities into list 2.
01:04
And so now i can go to one variable statistics on list 1 and frequency as list 2.
01:12
And so we find our mean comes out to be a value of 1 .65.
01:17
Now, the standard deviation is calculated long hand by taking the difference between each of these values squared times the corresponding probability and do that for all three categories.
01:33
And then you will add those up in square root.
01:36
And that value comes out to be 0 .7263.
01:42
Now, the next part of your question says to number four to deal with the binomial that has an n of 25 and a probability of 0 .4.
01:55
And you want to compute the probability that x is less than or equal to 24...