00:01
It looks like we're working with the standard normal distribution.
00:04
And i think your first question is what is the area underneath this standard normal distribution that has a mean of zero and a standard deviation of one? and the area underneath this entire distribution is one.
00:17
And then it looks like you want to find what the area is between negative 2 .5 and 2 .5.
00:27
And so if you look up 2 .5 and find the area below 2 .5, that is 0 .9938, and the area below negative 0 .05 is 0 .0062, and that difference gives us the area between.
00:48
So it's close to all of it.
00:50
Now, when i look at the next part that you have, it looks like you just need the answer for a, the probability that z is greater than 1 .28.
01:00
And the probability that z is greater than 1 .28, here's 1 .28 on your drawing 1 .28, and you want this area.
01:13
And it's actually easier to look up the opposite and find the area below negative 1 .28, because then you don't have to subtract.
01:21
Otherwise, you're always looking up the table, is always giving you the area to the left of that number.
01:26
So negative 1 .28 corresponds with 0 .103.
01:38
And i believe that's all you had a question with.
01:41
When i look at, you know, you can use the values...