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.
The margin of error associated with this confidence interval is 20
Step-by-step explanation:
A confidence interval has two bounds, a lower bound and an upper bound. The interval is symmetric, which means that the margin of error is the difference between these two bounds(upper - lower), divided by 2.
In this problem, we have that:
Lower bound: 520
Upper bound: 560
Determine the margin of error associated with this confidence interval.
(560 - 520)/2 = 20
The margin of error associated with this confidence interval is 20
To evaluate the combination we proceed as follows: 21C3 Given nCk we shall have: n!/[(n-k)!k!] thus plugging the values in the expression we get: 21!/[(21-3)!3!] =21!/(18!×3!) =1330 Answer: 1330
