Make sure to show all work, round answers to two decimals.
1) A researcher is interested in determining how long people keep a smart phone before replacing it. The researcher took a random sample of 9 people, and found that the sample had an average time of replacing equal to 17.2 months, with a population standard deviation of 3.4 months. Build a 99% confidence interval about the true population mean, and interpret your results. Assume the variable is normally distributed.
2) A researcher is interested in determining how long people keep a smart phone before replacing it. The researcher took a random sample of 9 people, and found that the sample had an average time of replacing equal to 17.2 months, with a sample standard deviation of 3.4 months. Build a 99% confidence interval about the true population mean, and interpret your results. Assume the variable is normally distributed.