All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.

(i)

Scatter Diagram 10(i)
Scatter Diagram 10(i)

(ii)
(a) r = 0.9860
(b) r = 0.9907

(iii) Since the product moment correlation coefficient is close to 1 for (ib), the model F = c+ dv^2 is the better model.

(iv) From GC, the regression line of F on v^2 is

F = 0.024242v^2 + 3.1957

F = 0.0242v^2 + 3.20 (3SF)

When F=26, 26 = 0.024242v^2 + 3.1957

\Rightarrow v = 30.7

Since v is the independent or controlled variable, neither the regression line of v \text{~on~} F nor the regression line of v^2 \text{~on~} F should be used.

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