Determine the margin of error. An article in an educational journal discussing a non-conventional high school reading program reports a 95% confidence interval of (520, 560) for the average score on...

Determine the margin of error.

An article in an educational journal discussing a non-conventional high school reading program reports a 95% confidence interval of (520, 560) for the average score on the reading portion of the SAT.  The study was based on a random sample of 20 students and it was assumed that SAT scores would be approximately normally distributed.

Determine the margin of error associated with this confidence interval.

a) 15

b) 10

c) 5

d) 20

e) 40