An agriculturist wants to test the effects of four different fertilizers A, B, C, D on the yield of paddy. In order to eliminate sources of error due to variabilities in self-fertility, he used the fertilizers in Latin square arrangements given below where the numbers indicate yields in quintals per unit area. Perform an analysis of variance to decide whether there is a difference between the fertilizers at 5% level ofsignificance.

A18

C21

D25

B11

D22

B12

A15

C19

B15

A20

C23

D24

C22

D21

B10

A27