1. A company has a new process for manufacturing artificial amethysts. In a trial run, 46 amethysts are produces. The mean weight for these 46 gems is = 6.75 carats, and the standard deviation is .33 carat. Let μ be the mean weight of the distribution of all amethysts produced by a new process. Find a 95% confidence interval (Do a full write-up)
2. Suppose a random set of forty communities gave an average of x-bar = 147.8 reported cases of larceny per year. Assume that population standard deviation is known to be 39.9 cases per year. Find a 98% confidence interval (Do a full write-up)
3. The home run percentage is the number of home runs per 100 times at bat. A random sample of 43 professional baseball players gave the following data for home run percentages.
1.6 2.4 1.2 6.6 2.3 0.0 1.8 2.5 6.5 1.8 1.2 1.8
2.7 4.2 1.6 2.7 2.0 1.9 1.3 2.7 1.7 1.3 2.1 2.8
1.4 1.8 3.1 3.8 3.2 3.8 2.1 3.4 1.3 1.5 2.9 2.6
0.0 4.1 2.9 1.9 2.4 0.0 1.9
Compute a 90% confidence interval for the population mean μ of home run percentages for all professional baseball players.