Assume Monthly Advertising Expenditure is the independent variable. Store Monthly Profit Monthly Advertising expenditure A1 $13,593.02 $1,710.00 A2 $23,896.73 $1,983.00 A3 $9,932.64 $952.00 A4 $9,100.41 $1,009.00 A5 $15,220.08 $2,315.00 A6 $33,900.67 $2,197.00 A7 $6,935.36 $934.00 A8 $10,112.62 $2,375.00 A9 $9,155.14 $1,065.00 A10 $8,513.94 $812.00 A11 $7,933.25 $1,052.00 A12 $11,388.13 $2,234.00 A13 $26,299.72 $2,962.00 A14 $21,423.87 $1,699.00 A15 $21,430.21 $1,991.00 A16 $19,984.96 $2,181.00 A17 $11,575.09 $1,831.00 A18 $18,900.44 $1,819.00 A19 $21,815.24 $2,394.00 A20 $35,642.73 $2,296.00 What is the sum of squares...