In a pharmacological study, researchers measured the concentration of the brain chemical dopamine in six rats exposed to toluene and six control rats. (This is the same study described in Example 7.2.1.) The concentrations in the striatum region of the brain were as shown in the table.4

(a) Use a Wilcoxon-Mann-Whitney test to compare the treatments at α = 0.05. Use a non-directional alternative.
(b) Proceed as in part (a),but let the alternative hypothesis be that toluene increases dopamine concentration.

Transcribed Image Text:

Dopamine (ng/gm) Toluene 3,420 2,314 1.911 2,464 2,781 2,803 Control 1,820 1,843 1,397 1,803 2,539 1,990