Calculate the confidence interval (Statistics problem)

[RedonYellow]

I am trying to calculate the confidence interval for this problem using my T-84, and it's driving me mad because I'm so close to the correct answer. The problem is

Homework Statement

The answer to this problem is (22769.83, 30059.41) (This is an example problem.) When I try to duplicate this in my calculator, my answer is (22772,30058).

Homework Equations

I go to STAT>TESTS>7>STATS

The Attempt at a Solution

I put the data in like this
standard deviation: 8150
mean: 26414.62
n: 20
C-Level: 0.9544

Could someone tell me what I'm doing incorrectly, please.

 

[LCKurtz]

I'm not familiar with your calculator but my guess is some problem with the Z values. If you check you will see that 95.44% corresponds to a right and left tail are each of .0228 which in turn gives a z value of 2. Why don't you just check what 2 sample standard deviations from the sample mean get you?