An agricultural scientist claims that the mean yield of a new variety of wheat, the 'Aureum', is more than 6.5 tonnes per hectare. To test this claim, the scientist measures the yield, xxx, of a random sample of 25 plots and obtains the following statistics:
xˉ=6.81,s=0.75 \bar{x} = 6.81, \quad s = 0.75 xˉ=6.81,s=0.75The yield may be assumed to be normally distributed.
Stating your hypotheses clearly and using a 5% level of significance, test the scientist's claim.
The standard deviation of the yield for a standard wheat variety is 0.6.
Stating your hypotheses clearly, test at the 5% level of significance whether or not there is evidence that the variance of the yield for the Aureum variety is different from that of the standard variety.
130 exam-style questions on WJEC A Level Maths 4.3.2 Statistical hypothesis testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.