00:01
Okay, so i see that you need help with this problem.
00:04
And so the question asks, assume that x, the starting salary for education majors, is normally distributed with a mean of 46 ,292, and a standard deviation of 4 ,320.
00:32
So then it says the probability that a randomly selected major received a starting salary offer greater than 52 ,000.
00:45
So it's greater than 52 ,350.
00:58
So what you have to do is you have to find the z score.
01:02
So in order to do that, you have to take the 52 ,000, 350, and you have to minus 40.
01:09
26 ,292 and divide that by 4 ,320.
01:16
And then you're going to get 1 .4.
01:21
And so then the probability of x being greater than 52 ,350 equals the probability of the z score being greater than 1 .4 or less than 1 .4.
01:33
So the standard normal distribution table gives us cumulative probabilities as the cumulative area under the bell shape curve.
01:41
So the area under the bell shape curve that is to the right of z equals 1 .4 is the same as the probability that it's less than 1 .4.
01:52
That's the area to the left of z equals negative 1 .4.
01:56
So using the former the table indicates because you're not going to be in negative land.
02:01
The probability of the z score being greater than 1 .4 equals 0 .4 .0 .5 .5 .5.
02:09
0 .0808, which is 8 .08 % is your answer for number one for that first one.
02:22
Then question number two, the probability that a randomly selected education major received a starting salary between, so between 45 ,000, and 52 ,350.
02:39
So what you have to do is you have to find the area under the curve between the two z scores.
02:51
So we already know between 52 ,350 minus 46 ,292 ,000, divided by 400, 4 ,320 is 1 .4...