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 11-6,using an overall level of significance of 0.01,the critical value of the Studentised range Q used in calculating the critical range for the Tukey-Kramer procedure is ________.