A plant purifies its liquid waste and discharges the water into a local river. The EPA collects water specimens of the discharge of the plant and also water specimens in the river upstream from the plant. The average bacteria counts for each of six specimens taken from the two locations are given below:
Plant discharge 30.1 36.2 33.4 28.2 29.8 34.9
Upstream 29.7 30.3 26.4 27.3 31.7 32.3
Test whether the mean bacteria count for the plant discharge exceeds that for the upstream location, and state your conclusions.