Study of armyworm pheromones. A study was conducted to determine the effectiveness of pheromones produced by two different strains of fall armyworms: the corn-strain and the rice-strain (Journal of Chemical Ecology, Mar. 2013).

Both corn-strain and rice-strain male armyworms were released into a field containing a synthetic pheromone made from a corn-strain blend. A count of the number of males trapped by the pheromone was then determined. The experiment was conducted once in a corn field and then again in a grass field. The results are provided in the accompanying table.

a. Consider the corn field results. Construct a 90% confidence LO5 interval for the difference between the proportions of corn-strain and rice-strain males trapped by the pheromone.

b. Consider the grass field results. Construct a 90% confidence interval for the difference between the proportions of corn-strain and rice-strain males trapped by the pheromone.

c. Based on the confidence intervals, parts a and

b, what can you conclude about the effectiveness of a cornblend synthetic pheromone placed in a corn field? A grass field?

d. The researchers also want to compare the proportion of corn-strain males trapped in the corn field to the proportion of corn-strain males trapped in the grass field.

Carry out this comparison using a hypothesis test (at a = .10). What inference can you draw from the data?

e. Repeat part d for the proportions of rice-strain males trapped by the pheromone.

Corn Field Grass Field Number of corn-strain males released 112 215 Number trapped 86 164 Number of rice-strain males released 150 669 Number trapped 92 375