申論題

4. (15 points) A company that is looking at the time to failure of the parts (days) it uses decides to look
at an alternative supplier of the product. The data for the current supplier and for the new supplier are shown here.

Assume that the data are normally distributed.

(b) The compuny has decided that if the m longer than it is for the current supplier, it will switch suppliers. Should the company switch mean time to failure for the new su uppliers is signifcantly suppliers? (Please clearly state the null, the alternat use a= 0.05) (10 points) ative bypothesis, and the test statistic, and