The following table gives the number of units of production produced by four employees each using a different type of machine:
Employee                    Type of machine
M1        M2        M3        M4
E1                40        36        45        30
E2                38        42        50        41
E3                36        30        48        35
E4                46        47        52        44
Required:
Test the hypothesis that means production is the same for the four machines
Test the hypothesis that the employees do not differ with respect to mean productivity. (Use 5% level of significance). Hint: use two way analysis of variance.