percentage

Question

Students in a college course take a common final exam. The exam scores are
normally distributed with a mean of 76 and a standard deviation of 8.
Bob scored an 88.What percent of students scored lower than Bob?

Answer 1

Calculate the Z score:  z = (88-76)/8 = 1.5

 

Use a calculator (e.g. Ti-84 DISTR menu...) to find P(Z<1.5) or use a Standard Normal Distribution table to look up the decimal value (converting to percentage if your table has strict probabilities ≤1).