Exercise 1

Whether or not specifically asked, you should always (1) plot the data in any potentially useful way, (2) state the assumptions made, (3) comment on the appropriateness of these assumptions, and (4) consider alternative analyses.

1. Find the main effects and interaction from the following data:

Nickel (%)	Manganese (%)	Breaking strength (ft-lb)
0	1	35
3	1	46
0	2	42
3	2	40

The purpose of these four trials was to discover the effects of these two alloying elements (nickel and manganese) on the ductility of a certain product. Comment on the possible implications of these results.

2. Stating any assumptions you make, plot and analyze the following data:

Temperature	Concentration	Catalyst	Yield
-	-	-	60
+	-	-	77
-	+	-	59
+	+	-	68
-	-	+	57
+	-	+	83
-	+	+	45
+	+	+	85

The ranges for these variables are as follows:

Temperature

( deg F)

Concentration

(%)

Catalyst

160

180