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Data Analysis of City of Roseville Recyclable Materials <br />The results of each comparison are shown in several tables, along with the Project <br />Team's interpretation of the data. <br />The mean, and upper and lower 90% confidence intervals are provided along with a <br />column titled "Statistically Significant Difference". If there is a check mark in this <br />column, it indicates that the ranges of the lower and upper confidence intervals <br />between the two collection methods are statistically different. That is, there was no <br />overlap in the percentages and therefore the results between the two methods reflect a <br />statistically significant difference. <br />Comparison of the Monday Collection Routes <br />Two Monday collection routes were chosen by the City to be the pilot areas for the <br />single stream collection method. The main difference between the two areas was the <br />age of the housing stock. The first pilot route included older homes, typically with <br />detached, single car garages and higher density than the second pilot route. The <br />second route included newer homes, typically with attached, two stall garages, and <br />lower density than the first pilot route. <br />For the comparative analysis shown below, the composition results of the two Monday <br />routes during the pilot were combined into one data set for September and one data set <br />for October. <br />Table 4 <br />Comparison of Monday Routes -July and September <br /> Monday Dual Stream Routes' Monday Single Stream Routesz <br /> July September <br /> Statisticall <br /> y <br /> 90% Confidence 90% Confidence Significant <br /> Interval Interval Difference <br />Material Mean Lower Upper Mean Lower Upper <br />Category <br />Paper 57.9% 54.5% 61.3% 78.7% 75.0% 82.4% / <br />Metals 7.9% 7.3% 8.5% 2.8% 2.0% 3.6% / <br />Glass 19.7% 16.4% 23.0% 5.3% 4.4% 6.2% / <br />Plastic 10.7% 9.0% 12.4% 6.0% 4.8% 7.2% / <br />Contaminants 3.9% 2.1 % 5.7% 7.1 % 5.8% 8.4% / <br />Total3 100% n/a n/a 100% n/a n/a <br />~ Eight samples were sorted from two Monday routes. <br />z Four samples were sorted from two Monday routes. <br />s The totals may not equal the sum of the material categories due to rounding. <br />sr~os B-5 <br />