An entrant at a science fair has included information about temperature conversion in various forms, as shown. The variables F, C, and K represent temperatures in degrees Fahrenheit, degrees Celsius, and kelvin, respectively.

Equation A
F =
9
5
C + 32
Equation B
K = C + 273.15
Table C
Degrees Celsius kelvin
8 281.15
16 289.15
31 304.15

Is the relationship between degrees kelvin and degrees Celsius proportional? Complete the explanation to justify your answer in two different ways.

Using Equation B you see that the y−intercept is
5
, not 0, so the graph does not include the origin. Using Table C you see that the quotient of K and C is not constant. So, the relationship between degrees kelvin and degrees Celsius proportional.

Is the relationship between degrees Celsius and degrees Fahrenheit proportional? Why or why not?

The relationship between degrees Celsius and degrees Fahrenheit proportional because Equation A is in the form y = mx + b with F being used instead of y and C being used instead of x. The value of b is
3
, not 0.