Your Practice Set – Applications and Interpretation for IBDP Mathematics
( b )
SS � ( 32 � 32 ) � ( 33.5 �38 ) res
2 2
�(( 0.3 ( 140 ) � 2 ) � 46 ) � ( 42.5 �50 ) �(( 0.3 ( 180 ) � 2 ) � 60 )
2 2
2
SS � 84.5 A1 res
( c ) 97.6 % of the variability of the data is explained by the regression model .
( A1 ) for correct approach
A1
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Exercise 73
1 . The monthly rent prices of several flats are studied . The following table shows the distances x ( in km ) of five flats from the central railway station and the corresponding monthly rent prices y ( in USD ).
Distance ( x km ) 0.2 0.5 0.8 1.2 1.7 Monthly rent price ( y USD ) 1100 900 850 500 530
It is suggested that the relationship between the variables can be modelled by the regression equation y� �400x� 1130 .
( a ) Use the suggested model to write down the estimated monthly rent price of a flat when the distance between the flat and the central railway station is
( i ) 0.2 km ;
( ii ) 0.8 km ;
( iii ) 1.7 km .
( b ) Hence , calculate SS res
, the sum of square residuals .
It is given that the coefficient of determination of this model is 0.872 .
( c ) Interpret the coefficient of determination .
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