Your Practice Set – Applications and Interpretation for IBDP Mathematics
4 . The following table shows the annual rainfall x ( in cm ) of a region in 5 different years and the corresponding annual corn yield rate y ( in
1
% yr � ).
Annual rainfall ( x cm ) 57 55 53 51 49 Annual corn yield rate
�1
( y % yr )
6 5.9 5.4 5.4 5.15
( 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 .
( ii ) Explain what the intercept b represents .
( b ) ( i ) Write down the correlation coefficient .
[ 3 ]
( ii ) Write down the coefficient of determination .
( iii ) Hence , interpret the coefficient of determination . [ 3 ]
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