Instruction 11-7
an Agronomist Wants to Compare the Crop Yield

Instruction 11-7
An agronomist wants to compare the crop yield of three varieties of chickpea seeds. She plants 15 fields, five with each variety. She then measures the crop yield in bushels per acre. Treating this as a completely randomised design, the results are presented in the table that follows.
$\begin{array}{rrrr}\text { Trial}& \text { Smith }& \text { Walsh}& \text { Trevor }\\\hline1 & 11.1 & 19.0 & 14.6 \\2 & 13.5 & 18.0 & 15.7 \\3 & 15.3 & 19.8 & 16.8 \\4 & 14.6 & 19.6 & 16.7 \\5 & 9.8 & 16.6 & 15.2\end{array}$
-Referring to Instruction 11-7,what are the degrees of freedom of the F test statistic for testing the block effects?