SOLUTION: Student population of 4000 take a test. The mean is 610 and standard deviation is 60. How many students score 570 or higher?

SOLUTION: Student population of 4000 take a test. The mean is 610 and standard deviation is 60. How many students score 570 or higher?

Algebra.Com

Question 934850: Student population of 4000 take a test. The mean is 610 and standard deviation is 60. How many students score 570 or higher?
Answer by rothauserc(4718) (Show Source): You can put this solution on YOUR website!
Pr(X>570) = 1 - Pr(X<570)
calculate z-score for Pr(X<570)
z-score = (570 - 610) / 60 = −0.666666667 approx -0.67
Pr(X>570) = 1 - Pr(X<570) = 1 - 0.2514 = 0.7486
now 4000 * 0.7486 = 2994.4 = 2994 students

RELATED QUESTIONS
The test score of a math class with 800 students are distributed normally with a mean of... (answered by ikleyn)

In an standardized test the mean score of students is 560 and a standard deviation of 15. (answered by robertb)

Suppose that from the past experience a professor knows that the test score of a student... (answered by Boreal)

The mean score for a standardized test is 1700 points. The results are normally... (answered by reviewermath)

Students in a class take a test and the mean score is 95 and the standard deviation is 8. (answered by Theo)

Please help with this problem. A first year Calculus class test gave the... (answered by nabla)

The time required to finish a test is normally distributed with a mean of 60 minutes... (answered by robertb)

Suppose the yearly textbook expenses for a college student are normally distributed with... (answered by stanbon)

If 200 students write a test and the average score is 77%. With a standard deviation of... (answered by Fombitz)