Your Practice Set – Applications and Interpretation for IBDP Mathematics
( b ) ( i ) r � 0.8042297654 r � 0.804
A1
( ii )
2
R � 0.6467855156
2
R � A1 0.647
( iii ) 64.7 % of the variability of the data is explained by the regression model .
A1 [ 3 ]
Exercise 72
1 . The following table shows the age of a car x ( in years ) and the corresponding distance travelled y ( in km ).
Age of a car ( x years ) 3 5 7 9 10 10 Distance travelled ( y km ) 26000 28000 49000 47000 58000 82000
( a ) The relationship between the variables is modelled by the regression equation y �ax � b .
( i ) Write down the value of a and of b , giving the answers correct to the nearest integer .
( ii ) Hence , estimate the distance travelled of a car when its age is 4.5 years . [ 4 ]
( b ) ( i ) Write down the correlation coefficient .
( ii ) Write down the coefficient of determination .
( iii ) Hence , interpret the coefficient of determination . [ 3 ]
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