RES 342 8.48 and 8.64

# RES 342 8.48 and 8.64 - A sample of 20 pages was taken...

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Add new rows below as needed 0 260 356 403 536 0 268 369 428 536 268 396 469 536 162 338 403 536 536 130 (Data are from a project by MBA student Daniel R. Dalach.) Sample mean = x-bar = 346.5 The sample standard deviation is s = 170.38 (a) Construct a 95 percent confidence interval for the true mean. 95% C.I. is [346.5 – 79.74, 346.5 + 79.74] = [266.76, 426.24] (b) Why might normality be an issue here? The C.I. is a statement about the population. The sample of 20 might not have been randomly s (c) What sample size would be needed to obtain an error of ±10 square millimeters with 99 percent confid On solving, we get n = 1925 (d) If this is not a reasonable requirement, suggest one that is. 99% confidence is too tight for a distribution that is probably not normal. Reducing it to a, say, 9 p = 86/773 = 0.1112; q = 1 – p = 1 – 0.1112 = 0.8888 (a) Construct a 90 percent confidence interval for the proportion of all kernels that would not pop. For a 90% confidence interval, Margin of error E = 1.645 * SE = 1.645 * 0.0113 = 0.0186

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RES 342 8.48 and 8.64 - A sample of 20 pages was taken...

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