Four laboratories are being employed to perform chemical analysis. Samples of same material are sent to the laboratories for analysis as part of study to find out whether or not they give, on average, the same results. Suppose the distributions of results for laboratories are of the same shape but not normal. The analytical results of sample material are as follows:
A B C D
58.7 62.7 55.9 60.7
61.4 64.5 56.1 60.3
60.9 63.1 57.3 61.4
59.1 59.2 55.2 60.9
58.2 60.3 58.1 62.3
Test if the laboratories provide the same results on average. Use a = 0.005.