Instruction 19-6
an Agronomist Wants to Compare the Crop Yield

question 46

Short Answer

Instruction 19-6
An agronomist wants to compare the crop yield of three varieties of chickpea seeds. She plants all three varieties of the seeds on each of five different patches of fields. She then measures the crop yield in bushels per acre. Treating this as a randomised block design, the results are presented in the table that follows.
$$\begin{array} { | c | c | c | c | } \hline \text { Fields } & \text { Smith } & \text { Walsh } & \text { Trevor } \\\hline 1 & 11.1 & 19.0 & 14.6 \\\hline2 & 13.5 & 18.0 & 15.7 \\\hline 3 & 15.3 & 19.8 & 16.8 \\\hline 4 & 14.6 & 19.6 & 16.7 \\\hline 5& 9.8 & 16.6 & 15.2 \\\hline\end{array}$$ Below is the Minitab output of the Friedman rank test:
Friectman Test Yedd versus Varieties Felds
Friedmantest for Yield by Varieties blocked by Fields $S = 10.00 D F = 2 P = 0.007$

$\begin{array} { l l l l } \text { Varieties } & N & \text { EstMedian } & \text { Sum of Ranks } \\ & & & \\ \text { Smith } & 5 & 13.500 & 5.0 \\ \text { Trevor } & 5 & 15.667 & 10.0 \\ \text { Walsh } & 5 & 18.533 & 15.0 \end{array}$

$\text { Grand median }=15.900$

-Referring to Instruction 19-6,what is the value of the test statistic for the Friedman rank test for the difference in the medians?

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Definitions:

Area Chart

A graph that plots quantitative data over time, similar to a line chart, but with the area beneath the line filled in to emphasize volume.

Scatter Diagram

A scatter diagram, or scatter plot, is a type of graph used in statistics to visually represent the relationship between two variables, with points plotted to show the value of one variable depending on the value of the other.

Logical Function

In computing and mathematics, a function that evaluates a set of conditions and returns a true or false value.

IF

A conditional statement used in programming that executes a specific segment of code if a given condition is true.