D=45t what is tge constant proportionality

45 is the constant proportionality.

The constant is called the coefficient of proportionality or proportionality constant.

When two variables are directly proportional, this means that one variable is always the product of another variable and a constant. The effect of one variable varies directly on the changes of the other variable.

y = kx is the equation for direct proportion or direct variation.

y = is equivalent to D in the above problem

k = is the constant. equal to 45 in the above problem

x = is equivalent to t in the above problem.