Rosetta gauge for stress strain

[Mechaman]

Homework Statement

Homework Equations

The Attempt at a Solution

I'm trying to find the principal strain, then from that find stress. The poisons ratio should be around 0.3 for this experiment. My result is about 100 micro strain higher than what my class mates got. Can anyone see where I'm going wrong?

 

[JBA]

In the first element of your calculation you give the result of : (348 + 18) /2 to be 357; the result should be 183.

 

[Mechaman]

In the first element of your calculation you give the result of : (348 + 18) /2 to be 357; the result should be 183.

Amazing, I forgot to enclose the whole top line with brackets on my calculator and divide by 2. Thanks a lot for looking over it and seeing that.