What Is the Correct Stress Calculation for a Wire Under Tension?

[Pyrex]

Homework Statement

Calculate the stress in a wire of diameter 0.35mm when the tension in the wire is 50N.

Homework Equations

Stress=F/A

The Attempt at a Solution

0.25/2=0.125
0.125/100=1.25x10"-3

Pi x 0.00125"2 = 1.542x10"-5

50/1.542x10"-5 = 3242542.153 Pa


Are my workings correct?

 

[SteamKing]

Is the wire diameter 0.25 mm or 0.35 mm?