An experimental researcher makes measurements of the percentage of iron complexes present ing samples of soil. The variable, percentage of iron complexes, is normally distributed and the samples are...

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Extracted text: An experimental researcher makes measurements of the percentage of iron complexes present ing samples of soil. The variable, percentage of iron complexes, is normally distributed and the samples are independent. The data is below. First determine the confidence interval for the true standard deviation of the variable at the 90% confidence level, Then use the maximum value from the standard deviation confidence interval in the calculation of the confidence interval for the true mean of the variable at the 90% confidence level. Hints: Fill in the two columns of the table. Find the sum of each column. Determine s?. Use the Chi distribution and the formula to determine the C.I. for the standard deviation. Use the t-distribution to determine the C.I. for the mean. Your answers are the two C.I.. 3.20, 3.60, 3.00, 3.40, 3.40, 3.10, 3.40, 3.10, 3.30 s2 (n-1) E = ta/2 Jn nEx2-(Ex)² s2 (n-1) < x="" i-e=""><µ>< ĩ="" -="" e="">