00:01
First question looks like you've done a good job with that.
00:03
You drew the bell -shaped curve, and you had to go out three standard deviations in each direction.
00:12
So you put 1350 here, and then one standard deviation out, 1550.
00:19
Two standard deviations out, 1750, and then out to 1950.
00:26
Then going one standard deviation this way, 1150, and then 950.
00:32
And then 750 and then 750 and i'm going to just peek at your picture again make sure that's what you have that's what it looks like and then next it says use the empirical rule what percent are between 750 and 1750 so 750 and 1750 this one is two standard deviation so we know that between here and here within the mean plus or minus two standard deviations would be approximately 95%.
01:19
And we know that between this is three standard deviations below, so between here and here is 99 .7%.
01:32
So if we subtract those two, we can then add an take the 90s 9 .7 minus the 95 would give us approximately 4 .7%.
01:48
And then we want to divide that by 2.
01:50
And that's how much would be down here, that difference divided by 2.
01:55
So that would be 2 .35 % right in here.
02:00
So 95 % in here plus the 2 .35%.
02:07
So we would say using the impert 3 .5%, rule 97 .35%.
02:13
And let's see what you said.
02:16
Going back, you said 97 .5.
02:19
So there's where i would have a little bit of a difference with you.
02:25
I have that would be that 97 .35.
02:30
And you have something close to that, but that's what i would get with the, using the empirical rule.
02:36
Now it says next, what is the cutoff for the bottom 7 .35? percent in terms of the number of square feet.
02:45
And so we want to find the bottom 78 percent.
02:49
So let's look at that and we'll change colors...