00:01
Sophia took the graduate record examination, the gre, and she scored 160 on the verbal and 157 on the quantitative reasoning section.
00:15
The mean score for verbal was, excuse me, was 151 with a standard deviation of 7, and the mean score for quantitative was 153 with a mean score, a standard deviation, excuse me, of 7 .67.
00:35
So for verbal, our shorthand for the normal distribution is going to be n, the mu, and the standard deviation.
00:46
And for quantitative, it's going to be n because the normal distribution, 153, and 7 .67.
00:55
For part b, we're going to find the z score for each.
00:58
So the z score for verbal is going to be 160 minus 151 divided by 7, and that is 1 .29.
01:06
The z score for quantitative is 157 minus 153 divided by 7 .67, and that's .52.
01:19
So relative to others, which section did she do better on? she did better on the verbal section because she scored farther away from the mean.
01:28
So she scored 1 .29 standard deviations above the mean, as opposed to the quantitative where she scored 0 .52 above the mean.
01:38
So d find her percentile scores for the two exams.
01:40
So now what we're doing is we're looking at our z score of 1 .29 and we're checking our standard normal table and the z score 1 .29 has a probability of about 90.
01:55
So i'm going to put the 90th percentile here...