Question 381:

Asked on September 13, 2008

Tags: Z-Score

1

Answer:

No answer provided yet.

If the z-score for the number of students who made a B is .5, the number of students can be found by looking up the area under the normal curve above this z-score by using the z-score to percentile calculator (enter .5, 1-sided area). You should get 69.15%. That is the percent that made a B or higher, so it includes those that also got A's.

So 69.15% of the 200 students (138.3) made an A or a B. Since you said 60 made an A, then we subtract these students out and are left with (138.3-60) =  78.3 made a B. Round up or down to the nearest person depending on the context.