ETME360 E - Handout 
Probability in multi-sample experiments: SOLUTION
Use of the Z-function table.
R. Larson

1.         1000  samples are tested to failure in a 4-point bending fixture. The force required to cause failure of each specimen is measured under multi-sample conditions. The mean value of the force required to break the specimens was 275.00 lbf. The standard deviation of the data was found to be 17.50 lbf.  What is the probability that the breaking strength of a sample is greater than 290.00 lbf? Greater than 300.00 lbf? Greater than 325.00 lbf?

2.           If the sample size is increased to 10,000  specimens,  how many (What numerical quantity) of these parts would be expected to break if tested in the same 4-point bending fixture and subjected to a  load of 290 lbf? 300 lbf? 325.00 lbf?