Using exponential function concepts, it is found that the daily rate of change in the mass of the sample is of -4%, that is, the amount decays by 4%.
<h3>What is an exponential function?</h3>
A decaying exponential function is modeled by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
In this problem, the function is:

Hence:


1 - r < 1, hence the rate is negative, and the daily rate of change in the mass of the sample is of -4%.
You can learn more about exponential function concepts at brainly.com/question/25537936