PLTHIS IS REGRESSION SUBJECT

QUESTION 1 The purity of oxygen produced by a fractional distillation promss is thought to be related the percentage of hydrocarbons in the main condenser of the processing unit. Twenty samples are shown below. Hydrocarbon Purily ('13) (91>) PuriJ)r (91.) Hydrocarbon ('11.) 86.91 1.02 96.73 1.46 89.85 1.11 99.42 1.55 90.28 1.43 98.66 1.55 86.34 1.11 96.0? 1.55 92.58 1.01 93.65 1.40 87.33 0.95 81.31 1.15 86.29 1.11 95.00 1.01 91.86 0.8? 96.85 0.99 95.61 1.43 85.20 0.95 89.86 1.02 90.56 0.98 a} Fit a simple linear regression model to the data. (5 marks) b) Test for signicance of regression. Use a = 0.05. (5 marks) c) What percent of the total variability in purity is explained by this model? (4 marks) Find a 95% condence interval on the slope. Interpret the meaning of the 'I'Iterval obtained. (4 marks) Find a 95% Cl on the mean purity when the hydrocarbon percentage is 1.00. (5 marks) Compute an F test for lack oft. Use a = 0.05. (7 marks)