00:01
Okay, and your question, you're given information about average teacher salary in connecticut.
00:05
And that mean, average would be $57 ,337 with a standard deviation of $7 ,500.
00:12
We're trying to fund the probability in part a that a randomly selected teacher would have a salary of less than $52 ,000.
00:20
Now, we were told that the salaries thought a normal distribution, so we would just basically need to find the probability of being lower than 52 ,000 in a normal model where the mean is this given 57 ,337.
00:40
To do this, i'm going to use technology in a program called normal cdf.
00:48
And the way it works is we're going to type in the lower amount first.
00:53
So we're talking about going out here forever.
00:56
I'm just going to put zero.
00:57
That would be perfect.
00:59
I mean, far enough.
01:00
It'll get us an accurate enough answer.
01:02
Up to the 52 ,000, with a mean of $57 ,337, and a standard deviation of $7 ,500.
01:15
Now, on a texas instrument, ti -84, this is found under the second distribution menu.
01:23
Second's the first key, distribution's the next key.
01:29
So typing that in, we end up with 0 .2384.
01:48
Now, i'm checking here to see, does it tell me where to round my answer? so we'll stick with four decimal places...