A research company has designed three different systems to clean up oil spills. The following

table contains the results, measured by how much surface area (in square meters) is cleared in 1 hour. The data were found by testing each method in several trials. Are the three systems equally effective? Use the 0.05 level of significance

System A 55 60 63 56 59 55

System B 57 53 64 49 62

System C 66 52 61 57