A sample of an unknown chemical element naturally loses its mass over time. The relationship between the elapsed time $t$, in months, since the mass of the sample was initially measured, and its mass, $M(t)$, in grams, is modeled by the following function: ###$M(t)= 120\cdot \left(\dfrac{81}{625}\right)\^{\Large t}$ **Complete the following sentence about the rate of change in the mass of the sample.** *Round your answer to two decimal places.* The mass of the sample decays by a factor of $\dfrac35$ every [[☃ numeric-input 1]] months.