A copy machine company advertises that its copiers will make at least copies before requiring maintenance. A consumer research group tested the claim by collecting repair data for that model of copy machine in different regions of the country. The means of the numbers of copies made before the copier needed maintenance for each of the regions have been sorted and are listed in the table below.
What are the upper and lower bounds of the sample-to-sample variability? Predict the number of copies that can be made before a machine requires maintenance. Do you think the consumer research group will dispute the company’s claim?