Does the presence of small numbers of weeds reduce the yield of corn? Lamb's-quarter is a common weed in corn fields. A researcher planted corn at the same rate in 8 small plots of ground with, then weeded the corn rows by hand to allow no weeds in 4 randomly selected plots and exactly 3 lamb's-quarter plants per meter of row in the other 4 plots. Here are the yields of corn (bushels per acre) in each of the plots. Weeds per meter Yield (bushels / acre) 0 166.7 172.2 165.0 176.9 3 158.6 176.4 153.1 156.0

a) What is the claim of this research? What are the null hypotheses and alternative hypotheses?

b)In this research, what is the t-test statistic t-value?

c) Compare the t-value which you obtained from part

(b) with the t table, give the conclusion for this research.