SOLUTION: Samsung wants to know how long cell phone owners keep their phones before upgrading. A simple random sample of 23 cell phone owners results in a mean of 2.64 years and a standard
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Question 1086245: Samsung wants to know how long cell phone owners keep their phones before upgrading. A simple random sample of 23 cell phone owners results in a mean of 2.64 years and a standard deviation of 0.71 years. Assume the sample is drawn from a normally distributed population.
Find the 95% confidence interval of the population mean.
If you worked for Samsung and decided you wanted to be 99% confident that the sample mean is within 0.25 years of the population mean, how large of a sample would you need to take? Assume that σ=0.71 for this calculation.
Explain why the population parameter may NOT follow a normal distribution. Would you expect the data to show a positive or negative skew? Explain. If the data were not normally distributed, how would this affect the calculations for the confidence interval?
