The life in hours of a 75-watt light bulb is known to be normally distributed with o=25 hours. A random sample of 20 bulbs has a mean life of x = 1014 hours. 1. Construct a 95% two-sided confidence interval on the mean life. 2. Construct the lower confidence bound on the mean life. 3. Compare the lower bound this confidence interval with the one in part (1).

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Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.