I thought I answered this previously.
a-c. Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of each Z score. Multiply by 100.
d, e. Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (.20 and .30 respectively) and get each Z score. Insert into equation above to calculate each raw score.
The Graduate Record Exam has a combined verbal and quantitative mean of 1000 and a standard deviation of 200. Scores range from 200 to 1600 and are approximately normally distributed.
A. What percentage of the persons who take the test score above 1300?
b. What percentage score above 800?
c. What percentage score below 1200?
d. Above what score do 20 % of the test takers-score?
e. Above what score do 30 % of the test takers score?
1 answer
1 answer