QUESTION 4 (25 Marks) Table 4 shows the results of a study conducted on the yield (in grams) of a chemical produced when heated to different temperatures (in .C). The least square regression line approach was used to establish this relationship. Temperature (C) 20.4 18.7 15.2 27.9 k 30.1 13.8 Yield (grams) 50 65 80 100 75 120 45 Table 4 (a) Find, in terms of k, the coordinates of the point that the least square regression line passes through. (126.1+k 7 76 ;) (b) Given that the least square regression line of yield on temperature is Y = 1.1458 + 3.6194x, find k. (19.5 .C) (c) Interpret the regression coefficients. (1.1458 + 3.6194x) (d) Determine the correlation coefficient and interpret the result. (0.8266) (e) State THREE reasons why it is necessary to use the least square regression method. (f) What is the expected chemical production yield when the chemical process is heated to 50.C? Comment on your estimation. (182.1158g) (g) What is the increase in chemical production yield when the temperature is increased by 10 C? (36.194g) (h) State the variable types and level of measurement for yield and temperature