The model given is:
The term in the parentheses represents the change of rate of the model. If the number is the parentheses is less than 1, we call it <em>exponential decay</em>.
If the number in parentheses is bigger than 1, we call it exponential growth.
In this case, the correct option is "decaying"
The number in parentheses let's call it R, is:
Where r is the rate of change. To find it:
To convert to percentage, we convert by multiplying by 100::
The second answer is 0.45%
And since t is the time passed in hours, and has a "60" multiplying it, the last answer is: Every 60 hours
<em>The final answer is:</em>
The function is exponentially decaying at a rate of 0.45% evary 60 hours.