Residual levels of DDT were measured in the blood of fish in three different estuaries. The results were as follows:
A B C
15 6 26
11 21 11
27 9 9
9 13 17
At the alpha = 0.05 level of significance, is there a statistically significant difference between the three estuaries in terms of mean residual levels of DDT? Formulate and test the appropriate hypotheses.
To test if there is a difference in means across 3 or more groups, you use one-way ANOVA (if there were only 2 groups, you'd use a t-test).
The null hypothesis is that the mean levels of ...