1. Four catalysts that may affect the concentration of one component in a three-
component liquid mixture are being investigated. The following concentrations are
obtained from a completely randomized experiment:
Catalyst
Observations (ij)
1
2
3
4
1
58.2
56.3
50.1
52.9
2
57.2
54.5
54.2
49.9
3
58.4
57.0
m
50.0
4
55.8
55.3
51.7
5
55.2
Total
284.8 223.1 104.3+m
204.5
Assume that the data are normally distributed, yij~N(μā, ϲ), i = 1,2,3,4 and
1 ⤠j ⤠5.
a) Write a full linear model for this experiment and explain the terms.
b) Based on the model in part (a), obtain a formula for the residual for the
observation in the position m. Hence, estimate of m which make the
corresponding residual zero.
c) Analyze the data and draw conclusions. Use a = 0.05.
d) Test all pairs of means using the Fisher Least Significant Difference (LSD)
method with a = 0.05. Comment on your findings.
e) Describe briefly how to check the model assumptions.