exam1_sol

# exam1_sol - Exam I No. 1 2 Solution This is a test for...

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Exam I Summer ’99 No. Solution Version A Version B 1 This is a test for population mean with a large sample size ( n(=167) > 30 ). C A 2 You believe that the cars are not getting 430 miles from a full tank. Therefore, the correct hypothesis is Ho: μ > 430 Ha: μ < 430 D E 3 Z = (X bar - µ) / (s/√n) = (421 - 430) / (10.7/√167) = -10.87 E B 4 The p-value associated with Z score of -1.84 is .0329 ( .5-.4671 = .0329 ) C B 5 The p-value(=.087) is smaller than the significance level (=.1 ). Therefore, we Reject Ho , accepting Ha. A C 6 You have rejected the null hypothesis when in fact it is true. This is TYPE I error. ( See p.273 ) A C 7 421 + 1.96 ( 10.7/√167 ) = 419.38 to 422.62 C E 8 With a large sample size, we expect a small C.I. B D 9 [(8-1)2.4 2 + (14-1)2.6 2 ] / (8+14-2) = 6.41 ( See p.337 ) B D 10 The correct hypothesis is Ho: μ1 = μ2 Ha: μ1 ≠ μ2 D A 11 t = (56-54) / [2.069 * √(1/8 + 1/14)] = 2.181 ( See p.p. 338 - 339 ) A B 12 Using the t-table, with df = 8+14-2 = 20, the p-vale

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## This note was uploaded on 03/09/2011 for the course DSCI 3710 taught by Professor Dr.jay during the Spring '08 term at North Texas.

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exam1_sol - Exam I No. 1 2 Solution This is a test for...

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