Question

300 juniors at Central High School took the ACT last year. The scores were distributed normally with a mean of 24 and a standard deviation of 4. How many students scored above a 24?

Answer 1

150 students

Explanation:

According to statement we have the following information

number of juniors=n=300

mean score=24

standard deviation score=4

The number of students that score above 24 is determined by

Number of students score above 24=number of juniors* P(student score above 24)

P(student score above 24)=P(x>24)=P(x-mean/sd>24-24/4)=P(z>0)=0.5.

Students score above 24=np=300*0.5=150

Hence there are 150 students scored above 24.