A group of environmental engineers are studying mushroom-like slime molds as a potential food source for insects. (Journal of Natural History, May 2010.) In particular, they investigated which of six species of slime molds are most attractive to beetles inhabiting an Atlantic rain forest. A sample of 19 beetles feeding on slime mold was obtained and the species of slime mold was determined for each beetle. The number of beetles captured on each of the six species are given in the accompanying table. The researchers want to know if the relative frequency of occurrence of beetles differs for the six slime mold species.

a. Identify the categorical variable (and its levels) of interest in this study.

b. Set up the null and alternative hypothesis of interest to the researchers.

c. Find the test statistic and corresponding p-value.

d. The researchers found “no significant differences in the relative frequencies of occurrence” using α = .05. Do you agree?

e. Comment on the validity of the inference, part d. (Determine the expected cell counts.)

Transcribed Image Text:

SLIMEMOLD Slime mold species: LE TM AC AD HC HS Number of beetles: 3 2 7 3 1 3