In: Statistics and Probability
A study is made of amino acids in the hemolymph of millipedes. For a sample of four males and four females of each of three species, the following concentrations of the amino acid, alanine (in mg/100 ml), are determined:
Species 1 : (Male) 21.5, 19.6, 20.9, 22.8; (Female) 14.8, 15.6, 13.5, 16.4
Species 2: (Male) 14.5, 17.4, 15.0, 17.8; (Female) 12.1, 11.4, 12.7, 14.5
Species 3: (Male) 16.0, 20.3, 18.5, 19.3; (Female) 14.4, 14.7, 13.8, 12.0
a.) Test the hypothesis that there is no difference in mean hemolymph alanine concentration among the three species
b.) Test the hypothesis that there is no difference between males and females in mean hemolymph alanine concentration.
c.) Test the hypothesis that there is no interaction between sex and species in the mean concentration of alanine in hemolymph.
d.) Prepare a graph of the row, column, and cell means, and interpret it in terms of the results of the above hypothesis tests.
e.) If the null hypothesis of part a, above, is rejected, then perform a Tukey test to assess the mean differences among the species.