Explain your choice of answer to below questions

Suppose a small company that manufactures cereal bars own two scales that weigh their products (say A and B). Quality control manager in this company is concerned that scale A is erroneous. He takes a sample of 20 cereal bars and weigh each of them using both scales A and B. Assume that you were given a spread sheet that include weights of the 20 cereal bars reported by two scales.

Explain how you would approach testing the QC managers' concern. What type of tests/CI you would construct to help him make a decision? Mention of any assumptions you would check or any graphing techniques you would use to display the data.