A temperature of 59F equals 15C. A temperature of 68F equals 20C.

Question

Find the linear equation with ordered pairs(F,C) for these data points. Use this linear equation to find the celcius temperature when it si 77F.

Answer 1

Well!!!

 

Let us assume  A F + B = C ---- {1}

 

59F equals 15C ==> 59 A + B = 15 ......{2}

68F equals 20C ==> 68 A + B = 20.... {3}

 

Solving {2} and {3},

{3} - {2} ==> 9 A = 5 ==> A = 5/9

{2} ==> B = 15 - 59 A = 15 - 59 (5/9) = -160/9

 

Thus, the Equation for conversion: C = 5/9 F - 160/9 = 5 (F - 32) / 9

 

Now, at 77 F , C = 5(77-32)/9 = 25 deg C