16 . The following table shows the lengths x ( in cm ) of the forearm of three students and the corresponding heights y ( in cm ).
Forearm length ( x cm ) 24 26 28 Height ( y cm ) 160 160 173
Two different models are suggested to model the relationship between the variables . The following table shows the estimated heights under two models :
Forearm length ( cm ) x
2
Height ( y cm ) estimated by Model 1 Model 2 y �1.6x �81x � 1175 y�
33
28 161.4 33 28 x
( a ) Write down the values of
( i ) a ;
( ii ) b ;
( iii ) c ,
giving the answers correct to 1 decimal place . [ 3 ]
( b ) Hence , calculate SS res
, the sum of square residuals of the Model 2 .
[ 2 ] The model with the smaller sum of square residuals is selected . It is given that the sum of square residuals of the Model 1 is 277.68 .
( c ) Determine which model is selected . [ 1 ]
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