Question

The quality control director for a clothing manufacturer wanted to study the effect of operators and machines on the breaking strength (in pounds) of wool serge material. A batch of material was cut into square yard pieces and these were randomly assigned, two each, to all twelve combinations of four operators and three machines chosen specifically for the equipment. The results were as follows:

Operator	Machine I	Machine II	Machine III
A	110 117	109 114	113 122
B	108 114	102 106	118 114
C	107 105	104   101	102 108
D	111 110	107 109	115 124

At the .05 level of significance:

                                            

1. Is there an effect due to the operator? If so, describe the effect
2. Is there an effect due to the machine? If so, describe the effect

Answer 1

For the given data, using Two-way ANOVA:

(a)

For operator,

As,

So, we have evidence to conclude that there is significant effect due to operator

(b)

For machine,

As,

So, we have evidence to conclude that there is significant effect due to machine.