6. Almost all US lightrail systems use electric cars that run on tracks built at street level. The Federal Transit Administration claims lightrail is one of the safest modes of travel, with an accident rate of 0.99 accidents per million passenger miles as compared to 2.29 for buses. The following data show the miles of track and the weekday ridership in thousands of passengers for six lightrail systems (USA Today, January 7, 2003) City Cleveland Denver Portland Sacramento San San St. Diego Jose Louis Miles of 15 17 38 21 47 31 34 Track Ridership 15 3 5 81 3 1 75 30 42 (1000s) a. Use the data to develop an estimated equation that could be used to predict the ridership given the miles of track b. What is the mean weekday ridership for all the lightrail systems with 30 5. A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted in the following data: Speed 30 50 40 55 30 25 60 25 50 55 miles 28 25 25 23 30 32 21 35 26 25 per hour On investigation, it was found that the above data are non normal. Using an appropriate test, show if they are related. A publisher is interested in estimating the relationship between sales and number of sections of elementary statistics in each semester. The following data have been collected: Sales 33 38 24 61 52 45 65 82 29 63 50 79 No. of Sections 3 7 6 6 10 12 12 13 12 13 14 15 Calculate the sample coefficient of correlation and determination