Answer:
9.6 days
Step-by-step explanation:
You want to find t such that y = (1/2)·y₀. That is, you want to solve
... (1/2)y₀ = y₀·e^(-0.072t)
Dividing by y₀, you have
... 1/2 = e^(-0.072t)
and taking the natural log gives ..
... ln(0.5) = -0.072t
... ln(0.5)/-0.072 = t ≈ 9.627 . . . . divide by the coefficient of t
The half-life is approximately 9.6 days.
