Thomson Photo Works purchased several new, highly sophisticated processing machines. The production department needed some guidance with respect to qualifications needed by an operator. Is age a factor? Is the length of service as an operator important? In order to explore further the factors needed to estimate performance on the new processing machines, four variables were listed:

X$1=$ length of time an employee was in the industry

X$2=$ Mechanical aptitude test score

X$3=$ Prior on$-$the$-$job rating

X$4=$ Age

Performance on the new machine is designated Y$.$ Thirty employees were selected at random. Data were collected for each, and their performances on the new machines were recorded. A few results are:

Perfomance Length Mechanical Prior

on new of time in aptitude on$-$the$-$job

MAchine Industry Score Performance Age

Name Y X$1$ X$2$ X$3$ X$4$

Mike Miraglia $115731012536$

Sue Trythall $115839311629$

The equation is:

Y$=11\mathrm{.}4+0\mathrm{.}2$X$1+0\mathrm{.}486$X$2+0\mathrm{.}712$X$3+0\mathrm{.}009$X$4$