SOLUTION: 1. A 99% confidence interval estimate for a population mean was computed to be (29.2, 46.6). Determine the mean of the sample, which was used to determine the interval estimate (sh

Algebra ->  Probability-and-statistics -> SOLUTION: 1. A 99% confidence interval estimate for a population mean was computed to be (29.2, 46.6). Determine the mean of the sample, which was used to determine the interval estimate (sh      Log On


   

Question 367001: 1. A 99% confidence interval estimate for a population mean was computed to be (29.2, 46.6). Determine the mean of the sample, which was used to determine the interval estimate (show all work).
2. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 170 was taken, and the mean amount spent was $248.72. Assuming a standard deviation equal to $48.31, find the 90% confidence interval for m, the mean for all such families (show all work).
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
1. (29.2 + 46.6)/2 = 37.9, the sample mean.
2. 248.72 +-(1.645)*(48.31)/sqrt%28170%29= 248.72+-6.095, so the 90% C.I. is
(242.625, 254.815).