The average number of articles produce by two machines 200 and 250 with standard deviation 20 and 25 respectively on the basis of records of 25 days production. Can you regard both the machine equally efficient at 1% level of significance.

Question

The average number of articles  produce by two machines 200 and 250 with standard deviation 20 and 25 respectively on the basis of records of 25 days production. Can you regard both the machine equally efficient at 1% level of significance.

PsyDAG · Answer

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n (n = 25)

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

Abel lema · Answer

the average number of articles produced by two machines per day are 200 and 250 with standard deviation of 20 and 25 respectively on the basis of 25 days production. Can you regard both the machines equally efficient at 1% level of significance?