Applying the exponential function, it is found that the amount after 71 years is of 402 mg.
The exponential equation for the amount after t years is given by:
[tex]A(t) = 942e^{-0.012t}[/tex]
For the amount after 71 years, we find A(71), thus:
[tex]A(71) = 942e^{-0.012(71)} = 402[/tex]
The amount after 71 years is of 402 mg.
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