1. The calcium concentration (in wt %) of the mineral fluorite was analyzed five times by...

 

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1. The calcium concentration (in wt %) of the mineral fluorite was analyzed five times by two different analysts. Are the mean values for the two methods significantly different at the 95% confidence level (i.e. are there differences between the analysts at the stated confidence level)? (4 marks) Analyst A B Ca (w/w %) 0.0271 0.0271 0.0282 0.0279 0.0271 0.0275 0.0268 0.0263 0.0274 0.0269 2. An analyst is responsible for the routine monitoring of HBr, generated as a byproduct of a chemical process. Three different indicators were used to monitor for end point. Is the difference between bromothymol blue and methyl red significant at the 95% confidence level? Answer the same question for methyl red and bromocresol green. (6 marks) Mean HBr concentration (M) ( standard deviation) 0.09565 0.00225 Number of Measurements Indicator Bromothymol blue Methyl red 28 0.08686 0.00098 18 Bromocresol green 0.08641 0.00113 29 3. Lithium isotope ratios (Li/Li) were measured for a Standard Reference Material using two methods. The following data was collected. Use statistics to prove if any data points are outliers. Report the average and standard deviation for each method. Are the differences in the lithium isotope ratios significant at the 95% confidence level? (5 marks) Method 1: 0.082601, 0.082621, 0.082589, 0.082617, 0.082598, 0.082367, 0.082596 Method 2: 0.082604, 0.082542, 0.082599, 0.082550, 0.082583, 0.082561, 0.082545, 0.082593 1. The calcium concentration (in wt %) of the mineral fluorite was analyzed five times by two different analysts. Are the mean values for the two methods significantly different at the 95% confidence level (i.e. are there differences between the analysts at the stated confidence level)? (4 marks) Analyst A B Ca (w/w %) 0.0271 0.0271 0.0282 0.0279 0.0271 0.0275 0.0268 0.0263 0.0274 0.0269 2. An analyst is responsible for the routine monitoring of HBr, generated as a byproduct of a chemical process. Three different indicators were used to monitor for end point. Is the difference between bromothymol blue and methyl red significant at the 95% confidence level? Answer the same question for methyl red and bromocresol green. (6 marks) Mean HBr concentration (M) ( standard deviation) 0.09565 0.00225 Number of Measurements Indicator Bromothymol blue Methyl red 28 0.08686 0.00098 18 Bromocresol green 0.08641 0.00113 29 3. Lithium isotope ratios (Li/Li) were measured for a Standard Reference Material using two methods. The following data was collected. Use statistics to prove if any data points are outliers. Report the average and standard deviation for each method. Are the differences in the lithium isotope ratios significant at the 95% confidence level? (5 marks) Method 1: 0.082601, 0.082621, 0.082589, 0.082617, 0.082598, 0.082367, 0.082596 Method 2: 0.082604, 0.082542, 0.082599, 0.082550, 0.082583, 0.082561, 0.082545, 0.082593