SOLUTION: If nine software engineers were interviewed to develop an estimate for software lines of code. The mean estimate is 12480 lines of code with a standard deviation of 2000 lines of
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Question 1065076: If nine software engineers were interviewed to develop an estimate for software lines of code. The mean estimate is 12480 lines of code with a standard deviation of 2000 lines of code. Develop a 90 per cent confidence interval for the population mean. Carry to three decimal places
Would the correct answer be 10992 13968 Answer by rothauserc(4718) (Show Source):
You can put this solution on YOUR website! The sample mean is 12480 and the sample standard deviation is 2000
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We want a 90% confidence interval for the population mean
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alpha(a) is 1 - (90/100) = 0.10
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critical probability(p*) = 1 - (a/2) = 0.95
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because our sample size is < 30, we use the t-statistic
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degrees of freedom = 9 - 1 = 8
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we lookup in the students t-table the critical value(CV) that has 8 degrees of freedom and a p* of 0.95
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CV is 1.860
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margin of error(ME) = CV * standard deviation = 1.860 * 2000 = 3720
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95% confidence interval = 12480 + or - 3720 = (8760, 16200)
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