In tree crop spraying, an airblast sprayer was used with and without an air oscillator on grapefruit and orange trees in an experiment to evaluate the delivery of
a solution. Data for the four treatments (grapefruit trees with oscillator, grapefruit trees without oscillator, orange trees with oscillator, orange trees without
oscillator) consisted of 72 observations. The corresponding sample means and
sample standard deviations of the solution deposited in nanograms per square
centimeter (ng/cm2
) appear in Table 2.9.
(a) Analyze the data as a one-way layout by constructing the corresponding
ANOVA table. Are there significant differences between the treatments?
(Hint: The mean squared error can be calculated by pooling the sample
variances and the treatment sum of squares can be determined from the
sample means.)
*(b) The analysis in (a) assumes the error variance does not depend on the
particular treatment. Are the data consistent with this assumption?