00:01
So another way of saying to find the percentage of data that lies between z equals negative 0 .81 and 1 .53 is saying what is the probability that z falls between negative 0 .81 and 1 .53.
00:15
So to do this, we're going to look at the z table and find the cumulative probability that z is less than 1 .53 and that it's less than negative 0 .81.
00:27
So each of these values in here for different z values is going to give us the cumulative probability distribution of z or basically the percent of data that falls under the curve up until point z.
00:45
And so what we can do to find the percentage of data that falls between 0 .81 and 1 .53 is we can find where z equals 1 .53, say it's somewhere like right here, and where it's negative 0 .81.
01:02
And the value that the table gives us for z equals 1 .53 is going to be all of this in black.
01:10
And the value that the table gives us for z equals negative 0 .81 is going to be all the way up to here.
01:17
And so you see there's some overlap, right? so you can get to the percentage of day that it falls between them by subtracting the value.
01:36
You get that says the amount of data that's less than 1 .53 and subtracting from that the percentage of data that is less than negative 0 .81.
01:48
So now we need to figure out how to interpret this graph or this chart right here...