An Article in journal of the electro chemical society. describes an experiment to investigate the low-pressure vapor deposition of poly silicon. the experiment was carried out in a large capacity reactor. the reactor has several wafer positions, and four of these positions are selected a random. the response variable is film thickness uniformity. three replicates of the experiment were run, and the data show below. (a) state the hypothesis and conduct an analysis of variance at beta=0.05 to test the hypothesis that there is a difference in film thickness due to wafer position. (b) plot and analyze the residuals from the experiment and comment on model adequacy. Evaluate all three assumptions regarding the residuals. Use minitab to answer the questions and explain.

Uniformity	Wafer Position
Replicate	1	2	3	4
1	2.76	2.38	2.44	0.94
2	4.17	2.70	1.97	1.46
3	3.49	3.24	1.37	1.85