Are Thinner Aluminum Cans Weaker? Data Set 20 in Appendix B includes the measured axial loads (in pounds) of 175 cola cans that use aluminum 0.0109 in. thick. Before obtaining these sample results, the standard cans had a thickness of 0.0111 in.

and the mean axial load was 281.81 lb. When using the axial loads of the thinner cans in a test of the claim that the mean axial load is less than 281.81 lb, the TI-83 Plus calculator provides the accompanying display. (The display is based on the assumption that s is known to be 22.11 lb.) Assume that we are using a 0.01 significance level.

Interpret the results. Do the thinner cans appear to have a mean axial load less than 281.81 lb?

7-4 Beyond the Basics