(a) A random sample of states yielded the following numbers of local school districts and the corresponding numbers of secondary school. Is there a significant relationship between the data? (Find the correlation coefficient r) [2] School district (x) Secondary schools (y) 50 53 19 24 17 95 27 187 84 143 68 216 (a) r=0.401 (b) r=0.500 (c) r=0.501 (d) r = 0.301 (b) An educator wants to see how the number of absences for a student in her class affects the student's final grade. The data obtained from a sample is shown below. Use the regression line equation to compute the final grade if x = 11. No. of absences (x) 10 12 2 0 Final grade (y) 6 5 70 65 96 94 75 82 (i) The regression line equation is y=A+Bx y= (ii) When the absents are 11, his final grade_y= ? [2] [1] [2] 1231 Question 8 Randomly selected 100 components of a particular brand used in an industrial plant have been running continuously and their lifetimes noted. Pump failure data Class interval #pumps failed (frequency) (hours) 500-600 5 600-700 15 700-800 23 800-900 36 900-1000 21 Cumulative Frequency Failure Probability F(t) Total 100 Work out the Failure probability at various points of the time interval 500 1000 (hours)