Textbook Problem

Screw Length (cm)	Pipe Diameter (in.)
2.55	1.25
2.45	1.18
2.55	1.22
2.35	1.15
2.60	1.17
2.40	1.19
2.30	1.22
2.40	1.18
2.50	1.17
2.50	1.25

Determine the average, variance, and standard deviation for the following parts. The measured values are given in the accompanying table.