Exercise 4 (10 marks) A chemical company wishes to study the effect of extraction time on the efficiency of an extraction operation. Here are the descriptive statistics that were generated in SAS based on the extraction time (in minutes) and the extraction efficiency (y): The SAS System The CORR Procedure 2 Variables: time efficiency Covariance Matrix, DF = 9 time efficiency 138.8888889 106.1111111 106.1111111 119.1666667 time efficiency Simple Statistics Variable N Mean Std Dev Sum Minimum Maximum time efficiency 10 32.00000 11.78511 320.00000 15.00000 49.00000 63.50000 10.91635 635.00000 46.00000 80.00000 10 (a) Compute the sample correlation coefficient. (b) Is there evidence of a significant correlation between extraction time and extraction efficiency? Run the appropriate test at = 0.05. (c) Compute the equation of the line that best describes the relationship between extraction time and extraction efficiency. [Note: Extraction efficiency is the dependent variable.]