# Thread: Homework assignment samples

1. ## Homework assignment samples

Hello everyone,

I have a question about my homework assignment;

A number of samples were given with various measurement values Xi ( N/mm2 ) and frequencies fi ( a total of 73 samples were held) .

In question a, I calculated the average ( 20 N/mm2 ) and standard deviation ( s= 3,60 ) of the sample.

question b states: what is the strength with a 5-% probability of undercut. With which formula can I calculate this?

Thanks, Erwin.

2. ## Re: Homework assignment samples

I found something on the internet, is this the right formula? Does anyone know that? ;

Xk= x̄ - z * s

3. ## Re: Homework assignment samples

Is there anyone who can help me with this?

Thanks!