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Unformatted text preview: 2. A manufacturer of gunpowder has developed a new powder that is designed to produce a muzzle velocity of 3000 feet per second. In order to assess the true mean muzzle velocity, eight shells were loaded with the charge and the muzzle velocities were measured. The mean and standard deviation of the sample are calculated to be 2958.75 and 39.26 respectively. (a) Calculate a 95% confidence interval for the mean muzzle velocity. (b) State clearly the assumptions required for using the confidence interval in (a) (c) How would you interpret the confidence interval in (a) ? 3. In order to assess the proportion, p, of all US households that have a computer, a sample of 6841 US households are selected at random, of which 2470 have a computer. (a) Construct a 95% confidence interval for p. (b) If a 95% confidence interval for p of width 0.01 is required, how large should the sample size be? Give your reasoning....
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 Fall '07
 Bagwhandee
 Statistics, Normal Distribution, Standard Deviation, mean muzzle velocity

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