hw3_solutions

hw3_solutions - Homework 3 Solutions 8.12. (a) p the margin...

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Homework 3 Solutions 8.12. (a) p : ffi :0.4rir. The standard enor is SEp : JiQ - iW594: 0.008372, so the margin of error for 95% confi.dence is 1.96SEi :0.01641, and the interval is 0.4007 to 0.4335. (b) The margin of error depends on the confidence level (95Vo in both cases) and on SEp. The sample size for male athletes was 1.6 times larger than the sample for female athletes, making the males' SEp smalier, resulting in a smaller margin of error for men. (Another contributing factor to the smaller SEp for males was that p(l - p) was slightly smaller for men: 0.2320 compared to 0.2431for women.) 8.1a. (a) The standard error is SEp : ^r/@39[0.3T1f1048 40.01429, so the margin of error for 95Vo confidence is 1.96SEp:0.02800 and the interval is 0.6620 to 0.7180. (b) To test Ho: p:0.79 vs. f1o: p <0.79, the standard error is op: J@3\@2Tfffr48:0.01258 and the test statistic is z = ffi*# : -1 .95. This is very strong evidence against I{s (P < 0.00005). 8,22, (a) Because we have deflned p as the proportion who prefer fresh-brewed coffee, we should compute p : # : 0.J.To test Ho: p: 0.5 vs. Ho:
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This note was uploaded on 02/24/2011 for the course STAT 3022 taught by Professor Staff during the Spring '08 term at Minnesota.

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hw3_solutions - Homework 3 Solutions 8.12. (a) p the margin...

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