The function is supposed to be
f(t) =87000/(1+1449e^-1.2t)
We can find the number of people ill after 8 weeks using the function above. We simply have to substitute 9 into t and solve for f(t)
f(9) = 87000/(1 + 1449e^-1.2(9))
f(9) = 84,502
After 9 weeks, there will be 84,502 infected people