when trying to find uncertanty percent error and your given the number - 15 s^-2 m with a implied uncertanty of +/- 1 s^-2 m and you try to find the percent uncertanty and you do this

Question

(- 15 s^2 m)^-1 1 s^-2 m (100 %) is the percent negative or positve

also when trying to find the average percent uncertanty of your data do you count that number as positive or negetive when you find the average by finding the mean?

Answer 1

In the example you mentioned, the relative uncertainty is +/- 1/15 = +/- 6.7%

I am not sure what you mean by your second question. When you make a series of measurements of something that should be a constant, the most probable value is the mean, unless there are systematic bias errors. Errors due to nonrepeatability are expressed as +/- about the mean in most cases. The error value can be estimated from the standard deviation, which is the square root of the average squared deviation from the mean.