A tensile test is performed on a $9mm$ thick sample of polyethylene $($LDPE$)$ of width $25mm.$ The sample was tested to fracture at room temperature and which point the sample had a total length of $71mm$ and the force measured was $4\mathrm{.}4kN.$

Given that the original length was $65mm,$ calculate the following to $2$ decimal places:

a$)$

The stress $$ at the point of failure

$=,$ Mpa