12.29 A power plant that uses water from the surrounding bay for cooling its condensors is required by the EPA to determine whether discharging its heated water into the bay has a detrimental effect on the flora (plant life) in the water. The EPA requests that the power plant make its investigation at three strategically chosen locations, called stations. Stations 1 and 2 are located near the plant’s discharge tubes, while Station 3 is located farther out in the bay. During one randomly selected day in each of four months, a diver sent down to each of the stations randomly samples a square-meter area of the bottom and counts the number of blades of the different types of grasses present. The result are listed the table below for one important grass type:

a Is there sufficient evidence to indicate that the mean number of blades found per square meter per month differs for the three stations?
Use 0.05.
b Is there sufficient evidence to indicate that the mean number of blades found per square meter differs across the four months? Use 0.05.

Transcribed Image Text:

Station Month 1 2 3 May June July August 2222 28 31 53 25 22 61 37 30 56 20 26 48