Assignment 2 URBS 336

Questions Involving Hand Calculations Question 1 Following political pressure from residents of Canterbury Street, funding is now available to install a noise barrier. Different approaches can be taken to install a barrier. The choice of the approach is important because it can lead to different proportions of gaps. Previous studies have shown a link between the percentage of area occupied by gaps and the reduction in noise level. Using the data available below, please confirm if such a relationship exists. In case of a significant relationship, what is the decrease in decibels if we have a percentage of gaps of five percent (bonus of 0.3 points for an adequate and detailed answer)? Percentage of Gap, Noise Reduction, and Calculations Reading Percentage (p) Noise reduction (n) A 25.0 0 17.90 320.56 -8.43 71.04 -150.91 B 13.0 3 5.90 34.86 -5.43 29.47 -32.05 C 6.0 6 -1.10 1.20 -2.43 5.90 2.66 D 3.0 9 -4.10 16.77 0.57 0.33 -2.34 E 1.5 11 -5.60 31.31 2.57 6.61 -14.39 F 0.8 14 -6.32 39.89 5.57 31.04 -35.19 G 0.4 16 -6.71 44.97 7.57 57.33 -50.77 Sums 49.7 59 0.00 489.57 0.00 201.71 -282.99 ( p − ) p ¯ ( p − p ¯) 2 ( n − ) n ¯ ( n − n ¯) 2 ( p − )( n − ) p ¯ n ¯