Please plot my data to test

Hi All

I have a set of data that I need to plot them , but excel gives strange results, shall you please help me to figure out this stress-strain curve ? I need the y as a function of x , best fit curve

also , is there a possibility to plot data online in this website ?

[Stephen23]

How is this related to MATLAB?

[farzad]

I just need to re calculate it , anyone who knows how to plot data could be kind to me and do this for me