Standard Deviation-3

Question

The mean Algebra 2 test score is 81.5, with a standard deviation of 5.1. There are 130 students taking the course. Assuming a normally distributed curve, how many students scored between 76.4 and 86.6? Remember: You can't have a fraction of a person. Round if necessary.  (Remember to use the percents given by the book: 2.35%, 13.5%, 34%.) 

Answer 1

z₁ = (76.6 - 81.5) / 5.1

z₁ = -0.961

19.489%

z₂ = (86.6 - 81.5) / 5.1

z₂ = 1

84.134%

84.134% - 19.489% = 64.645%

Can you calculate the number of students and anwer?