Here's the question:(adsbygoogle = window.adsbygoogle || []).push({});

so, I said the mean (X) of delta is 0.0015 and the standard deviation (S) of delta is 0.000092 In the expression for uniaxial strain e = d/l, the elongation is specified as

d ~ N(0.0015, 0.000092) in. and the length l ~ N(2.0000, 0.0081) in.

What are the mean, standard deviation, and coefficient of variation of the corresponding strain e?

[tex]X_d=0.0015, S_d=0.000092[/tex]

[tex]X_l=2.000, S_l=0.0081[/tex]

I said [tex]Z=d/l\ thus\ X_z=X_d/X_l[/tex] and the [tex]S_z^2=(C_d^2+C_l^2)/X_z^2[/tex]

So, I did the following: [tex]X_e=X_d/X_l=0.0015/2.000=0.00075[/tex]

and [tex]S_z=\sqrt{((0.000092/0.0015)^2+(0.0081/2.000)^2)/0.00075^2}=81.956[/tex]

The last part doesn't seem right though. Any thoughts?

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Mean, and standard deviation question.

**Physics Forums | Science Articles, Homework Help, Discussion**