x000 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

x=[0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00];

y=[-720.57 -752.16 -752.11 -769.84 -791.13 -803.85 -813.57 -811.46 -830.41 -834.86 -845.90 -851.27 -842.79 -829.86 -840.71 -838.15 -825.67 -801.66 -814.97 -804.81 -774.00 -773.63 -766.35 -732.38 -717.68];

here is x and y

Solution

>> x = [0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00];
>> y=[-720.57 -752.16 -752.11 -769.84 -791.13 -803.85 -813.57 -811.46 -830.41 -834.86 -845.90 -851.27 -842.79 -829.86 -840.71 -838.15 -825.67 -801.66 -814.97 -804.81 -774.00 -773.63 -766.35 -732.38 -717.68];
>> p = polyfit(x,y,2)

p =

0.8423 -19.9949 -722.7508

>> x1=[7 19 22.2];
>> y1=(0.8423.*x1.*x1)-19.9949.*x1 -722.7508

y1 =

-821.4424 -798.5836 -751.5184

>>