Mineral mining is one of the most important economicactivities in Chile. Mineral

Chapter 13, Problem 21

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Mineral mining is one of the most important economicactivities in Chile. Mineral products are frequently foundin saline systems composed largely of natural nitrates.Freshwater is often used as a leaching agent for theextraction of nitrate, but the Chilean mining regions havescarce freshwater resources. An alternative leaching agentis seawater. The authors of Recovery of Nitrates fromLeaching Solutions Using Seawater (Hydrometallurgy,2013: 100105) evaluated the recovery of nitrate ionsfrom discarded salts using freshwater and seawater leachingagents. Here is data on x 5 leaching time (h) and y 5nitrate extraction percentage (seawater):x 25.5 31.5 37.5 43.5 49.5 55.5y 26.4 40.1 50.2 57.4 62.7 67.3x 61.5 67.5 73.5 79.5 85.5 91.5y 71.4 74.7 77.8 80.3 82.3 84.1x 97.5 103.5 109.5 115.5 121.5 127.5y 85.5 86.6 87.9 89.0 89.9 90.6x 133.5 139.5 145.5 151.5 157.5y 91.2 91.8 92.3 92.8 93.3a. Construct a scatterplot. If the simple linear regressionmodel were fit to this data, what would a plot ofthe (x, e*) pairs look like?b. Construct a scatterplot of y versus x9 5 1/x andspeculate on the value of r2 after fitting the simplelinear regression model to the transformed data.c. Obtain a 95% prediction interval for nitrogen extractionpercentage when leaching time 5 100 h