Question: A battery company claims that its batteries last an average of 100 hours under normal use. There have been several complaints that the batteries don’t last that long so an independent testing agency is engaged to test them. For the 16 batteries tested, the mean lifetime was 97 hours with a standard deviation of 12 hours.

a) What are the null and alternative hypotheses?

b) What assumptions should be made before we proceed?

c) At a 5% level of significance, what do you conclude?

d) State the p-value and interpret its meaning.