From data (-4,1),(-1,2),(2,7) and (3,1) , the regression line of y on x is obtained as y=a+b x , then what is the value of 2 a+15 b ?

Step-by-step solution

array |c|c|c|c| x & y & x y & x^2 -4 & 1 & -4 & 16 -1 & 2 & -2 & 1 2 & 7 & 14 & 4 3 & 1 & 3 & 9 array aligned x & =0, y=11, x y=11 x^2 & =30 x & = 0 4 =0, y = 11 4 b_ y x & = x y- x y 4 x^2- ( x)^2 4 & = 11-0 30-0 = 11 30 aligned Equation of regression line of y on x will be array rlrl & & y- y & =b_ y x (x- x ) & y- 11 4 & = 11 30 (x-0) & y & = 11 30 x+ 11 4 array aligned a & = 11 4 and b= 11 30 2 a+15 b & =2 11 4 +15 11 30 =11 aligned