finding the z-score

Question

What is the z-score for someone in the top 3% of their class?

A. -1.88

B. 0.97

C. 1.88

D. 0.3

E. 1.3

Answer 1

A normally distributed graph has an area under the curve of 1.000 (100%). The area under the graph is the percentage.

When you read a z-table the area starts at 0 and goes to 1.0, with the mean at .5 (50%).

So, 3% = 3/100 = .03 is the bottom 3%

The top 3% is above 97% = .9700

From a z-table if you look for .9700 you will find z = 1.88

C.