Using exponential function concepts, it is found that it represents a decay of 0.9%.
A decaying exponential function is modeled by:
[tex]A(t) = A(0)(1 - r)^t[/tex]
In which:
In this problem, the function is:
[tex]A(t) = 9300(0.991)^{6t}[/tex]
Hence:
[tex]1 - r = 0.991[/tex]
[tex]r = 0.009[/tex]
Thus, it represents a decay of 0.9%.
You can learn more about exponential function concepts at https://brainly.com/question/25537936