Page:Biometrika - Volume 6, Issue 1.djvu/24

24 “and the quality of the resulting barley is inferior though the yield may be greater.”

In this case I propose to use the approximation given by the normal curve with standard deviation $$\frac{s}{\sqrt{(n-3)}}$$ and therefore use Sheppard’s tables, looking up the difference divided by $$\frac{s}{\sqrt{8}}$$. The probability in the case of yield of corn per acre is given by looking up $$\frac{33.7}{22.3}=1.51$$ in Sheppard’s tables. This gives $$p=.934$$, or the odds are about 14:1 that kiln-dried corn gives the higher yield.

Similarly $$\frac{.91}{.28}=3.25$$, corresponding to $$p=.9994$$, so that the odds are very great that kiln-dried seed gives barley of a worse quality than seed which has not been kiln-dried.

Similarly it is about 11 to 1 that kiln-dried seed gives more straw and about 2:1 that the total value of the crop is less with kiln-dried seed.