Question: Batteries A company that produces AA batteries tests the lifetime of a random sample of 30 batteries using a special device designed to imitate real-world use. Based on the testing, the company makes the following statement: "Our AA batteries last an average of 430 to 470 minutes, and our confidence in that interval is 95%."33
(a) Determine the point estimate, margin of error, standard error, and sample standard deviation.
(b) A reporter translates the statistical announcement into "plain English" as follows: "If you buy one of this company's AA batteries, there is a 95% chance that it will last between 430 and 470 minutes." Comment on this interpretation.
(c) Your friend, who has just started studying statistics, claims that if you select 40 more AA batteries at random from those manufactured by this company, there is a 95% probability that the mean lifetime will fall between 430 and 470 minutes. Do you agree? Explain.
(d) Give a statistically correct interpretation of the confidence level that could be published in a newspaper report.