If X = 94, S = 25, and n = 16, and assuming that the population is normally distributed, construct a 95% confidence interval estimate of the population mean, μ.
2. A marketing researcher wants to estimate the mean amount spent ($) on a certain retail website by members of the website's premium program. A random sample of 91 members of the website's premium program who recently made a purchase on the website yielded a mean of $1800 and a standard deviation of $250. Complete parts (a) and (b) below.
A. Construct a 90% confidence interval estimate for the mean spending for all shoppers who are members of the website's premium program.
3. Assuming that the population is normally distributed, construct a 99% confidence interval for the population mean for each of the samples below. Explain why these two samples produce different confidence intervals even though they have the same mean and range.
Sample A:
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Full data set
Sample B:
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Construct a 99% confidence interval for the population mean for sample A.