Calculate the standard deviance (statistics)

[RedonYellow]

1. The problem statement, all variables and given/known data

From this table of values, I'm supposed to calculate the standard deviance

http://i233.photobucket.com/albums/ee90/IrisChan7/dm2-1.jpg

2. Relevant equations

Up until this point, I've had no problem calculating the standard deviance with my calculator by going to STAT> CALC > 1 and entering the table.

3. The attempt at a solution

This is was my method of solving it this time, and my answer was 4.40. However, the answer in the example says to "Assume that the standard deviance is 3.50." I don't understand the basis of making such an assumption. How can I calculate the standard deviance in a way that will result in 3.50 as my answer?

[Stephen Tashi]

However, the answer in the example says to "Assume that the standard deviance is 3.50." I don't understand the basis of making such an assumption.

If the question is saying to assume the population standard deviation is 3.5, this does not contradict getting a different answer for the sample standard deviation, which is what you calculated.

The only wiggle room that I see for you in calculating the sample standard deviation is whether you divide by 19 (the samle size minus 1) or 20 (the sample size). I haven't checked the arithmetic you did.

[RedonYellow]

Never mind. I figured it out