February 18th, 2020
Two different batteries are being considered for an industrial application. A random sample of 30 of Battery A produces a mean of 16.4 hours of useful voltage with a standard deviation of 3.2 hours. A sample of 30 of Battery B produces a mean of 18.1 hours with a standard deviation of 2.7 hours. The researcher is interested in finding evidence at the .05 level that Battery A has a shorter average than Battery B.
Which of the following pairs of hypotheses correctly characterizes the question of interest?
What’s the value of the test statistic (using sample A as sample 1)?
What is the p-value?
What is the correct decision?