Statistics
posted by Cam on .
A random sample of 50 students chosen from an elementary school with 400 students was found to have a mean allowance of $26 per week with a standard deviation of $8. Obtain a 98% confidence interval for the total amount of allowance money given to students in this school per week.

262.33*8/sqrt((50)), 26+ 2.33*8/sqrt((50)),
= ( , ) ? 
That's what I originally did but it's not one of the correct answers

[ 23.37, 28.63]

$9,531 to $11,269
$9,347 to $11,453
$10,028 to $10,772
$9,414 to $11,386
Are my multiple choice 
mean 26(400) = $10400
Standard deviation = 8(400) = 3200
10400+ 2.3263*3200/sqrt(50))
[$9,347, 11,453] 
Thank you so much !