Question

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. 20
B. 10
C. 15
D. 40
E. 5

Answer 1

Option A is right

Explanation:

Given that 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.

Let X be the score on the reading portion of the SAT.

By central limit theorem x bar, the sample mean will follow a normal.

95% confidence interval shows that mean

= average of the two limits

= 540

Margin of error = upper bound of confidence interval - Mean

=
`560-540=20`

Option A is right