# Math Help - My answer doesn't match the book

1. ## My answer doesn't match the book

I have a book with two examples for calcuating Confidence interval and it displays the answer, however I can't come up with the same answer. So, What is the answer to these two questions.

24.1 - 1.96 * (10/5.47) =

24.1 + 1.96 * (10/5.47) =

My answer is almost double what the book has.

2. Originally Posted by Swagg
I have a book with two examples for calcuating Confidence interval and it displays the answer, however I can't come up with the same answer. So, What is the answer to these two questions.

24.1 - 1.96 * (10/5.47) =

24.1 + 1.96 * (10/5.47) =

My answer is almost double what the book has.
$\frac{10}{5.47} = 1.828$

$1.828*1.96 = 3.583$

$24.1 \pm 3.583 = [20.517, 27.683]$

3. Not my answer, it was the books answer, however I see my mistake.

Thank You.