Important Notes:
For each assignment question
• State your null hypothesis.
• Carry out manual calculations and complete the analysis of variance (ANOVA) table.
• Make a decision about the null hypothesis.
• Carry out mean comparison and make a recommendation on which treatment(s) would you
recommend for the farmers.
• Do not submit statistical software outputs
Question 3 [20 marks]
A N-fertiliser rate trial consisted of four rates including a control (0, 50, 100, and 150 kg/ha),
assigned randomly to five field plots in a randomized complete block randomized experiment
design. The resulting maize grain yields (t/ha) are shown in the table below:
Block
0 kg/ha
50 kg/ha 100 kg/ha 150 kg/ha
I
1.2
1.5
2.5
2.0
II
1.1
1.7
2.7
2.2
III
1.3
1.8
2.8
2.3
IV
1.0
1.6
2.6
2.1
V
1.2
1.7
2.7
2.0
a. Investigate the effect of N-rates on the grain yield of maize.
b. Which of the tested N rate(s) would you recommend to farmers?
c. Was the experimenter correct in selecting this experimental design for this research?
Comment.