Question 1 Marks The marks obtained in a Statistics test are shown in the table below. 70 - 79 80 - 89 10 - 19 20 - 29 30 - 39 40 - 49 50 - 59 60-69 Frequency 6 8 11 9 15 13 18 20 a. Draw a suitable cumulative frequency curve for the distribution (8 marks) b. Using the curve, determine: (2 marks) i. the median (5 marks) ii. the Quartile Deviation Question 2 Two judges used a scale 0 - 10 to independently rate the performances of 8 contestants at a concert. Judge I(x) 5 7 3 7 19 6 5 8 Judge 2(y) 7 8 6 9 4 9 a. Calculate the correlation coefficient and interpret your answer (10 marks) b. Determine the equation of the regression line. (5 marks) Question 3 The table below shows the probability distribution for a discrete random variable X. X 0 1 2 4 5 P(X=x) 0.15 0.20 0.30 10.10 a. State the value of n. (2 mark) b. Calculate the expected value, E(x). (3 marks) c. Calculate the variance, Var(x). (5 marks) The Council of Community Colleges of Jamaica Page 2 Question 4 A. A random variable X follows a Normal probability distribution and has a mean value of 25 and a variance of 9. Calculate: i. P(X > 26) (3 marks) ii. P( 23