The constant of proportionality in terms of the cost per text is the coefficient of 
in the equation 
. Since the coefficient of is 0.25, the constant of proportionality in terms of the cost per text is 0.25.
Proportionality constants are usually expressed as fractions, so lets convert 0.25 to a fraction. To do that we are going to add the denominator 1 to our decimal, and then we will multiply both numerator and denominator by ten for every number after the decimal point:
Finally, we can simplify our fraction:
We can conclude that the constant of proportionality in text of the cost per text is 1/4
Proportionality constants are usually expressed as fractions, so lets convert 0.25 to a fraction. To do that we are going to add the denominator 1 to our decimal, and then we will multiply both numerator and denominator by ten for every number after the decimal point:
Finally, we can simplify our fraction:
We can conclude that the constant of proportionality in text of the cost per text is 1/4