A cell phone manufacturer claims that the batteries in itslatest model provide 20 hours of continuous use. In order to verifythis claim, and independent testing firm checks the battery life of100 phones. They find that the batteries in these 100 phones lastan average of 19 hours with a standard deviation of 5 hours.Conduct an appropriate hypothesis test to check whether the resultsfrom this sample provide sufficient evidence that the true meanbattery life is significantly less than 20 hours.
- Is this a question about the sample mean or the sampleproportion? Explain how you know.
- What is the most appropriate test, a two-tailed test, aright-tailed test, or a left-tailed test? Explain how youknow.
- State the null and alternative hypotheses. Make sure to useproper notation.
- Calculate the test statistic. Make sure to show all yourcomputations.
- Determine the P-value. Make sure to explain how you obtainedthe value.
f. State the decision about the null hypothesis as well as theconclusion from your hypothesis test in the context of theproblem.
