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1.A sample of 6 adults elephant had an average weight of 12, 200 pounds,

with a sample standard deviation of 200 pounds. Find the 95% interval for the population mean.

2.A sample of 15 waitresses showed an average weekly income of $320.20. The standard deviation of the sample was $12. Find the 98% confidence interval of the population mean.

3.A company has a new process for manufacturing large artificial sapphires. In a trial run, 41 sapphires are produced. The mean weight was x = 6.75 carats and the standard deviation s = 0.33 carat. Find the 95% confidence interval for the population mean.

4.The discovery of an archaeologist shows that the mean of seven fossil skeletons from a previous Unknown species of miniature horses is 46.14 with a sample standard deviation s = 1.19. Find a 99% confidence interval for the true population mean.