All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.
(a)
(i)
Graph of 8ai
(ii)
Graph of 8aii
(b)
(i)
Model A: 
Model B: 
(ii) Since the 
is close to 1 for Model B, Model B is the better model.
(3 S.F.)
(iii) Required estimated price 
Personal comments:
(a) is rather straight forward so long as you follow the given instructions, bear in mind the graph is quadratic in nature. Since no scatter was drawn in part (b), we can simply justify the choice of regression model using the r-value found.
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