00:01
We're looking at a normal distribution.
00:03
So i'll draw it out, although we have a normal curve here.
00:09
And the mean, mu, is 62 inches, standard deviation, 1 .7 inches.
00:17
Okay, and it recommends using the figure -given.
00:20
So what we see here is called the empirical rule.
00:25
And the empirical rule is telling you that a certain percentage of values are within a certain number of standard deviations.
00:32
It works for any distribution that is symmetric and unimodal, so bell -shaped, approximately normal, normal.
00:39
Sometimes it's called the 68, 95, 99 .7 rule, and you can see why from the curve given.
00:48
Approximately 68 % of values are within one standard deviation, 95 % within 2, 99 .7 % within 3.
00:56
So for part a, we want the probability, or rather the percentage of women, but are taller than 62 inches.
01:06
So 62 is the mean.
01:08
We want to know how many are in this area here.
01:12
And the answer to that is 50%.
01:14
In a normal distribution, the mean, the median and the mode are all the same thing...