I've already unlocked a few of these examples with zero help explaining how we come up with the correct answer. I would appreciate help figuring this question out but more importantly, I need to know how exactly we came up with the correct answer. I cannot find any proper formulas or steps anywhere to assist.

The electric current i (in mA) in the circuit i=8.91e0.14t where t is the time (ins).

Evaluate i for t = 9.0 ms.

i=