2. (1 Opts) Suppose we are investigating the effects of four antirusting agents. A total of 40 ferric samples were available. Ten samples were randomly selected and assigned to one antirusting agent. A score between 0 and 100 was measured for each ferric sample. Higher number means better performance. Scores of the 40 samples were given in the following table \"__n __ _ _z_ _ _m- _m- __ ___ll_ _m-m-n Suppose there is no block effect (randomly complete design). 1) Please compare if the effects of the four antirusting agents are different. 2) Which group(s) give the best performance? Please explain why