Answer: [tex]y = 850(0.943)^t[/tex]
Reason:
The exponential of the form [tex]y = a*b^x[/tex] has 'a' as the initial term and b as the growth or decay factor.
a = 850 is the starting amount
b = 1 + r = 1 + (-0.057) = 0.943 is the decay factor
If the sample loses 5.7% of its mass each year, then it keeps the remaining 94.3% of it.
