Answer
$5.1m\leq d_o\lt\infty$.
Work Step by Step
Calculate the extreme object distances by using the lens equation with the focal length, and the maximum and minimum image distances.
$$\frac{1}{d_o}+\frac{1}{d_i}=\frac{1}{f}$$
$$d_{o,min}=\frac{fd_{i,max}}{ d_{i,max}-f }=\frac{(200.0mm)(208.2mm)}{ 208.2mm -200.0mm}= 5078mm\approx 5.1m$$
$$d_{o,max}=\frac{fd_{i,min}}{ d_{i,min}-f }=\frac{(200.0mm)(200.0mm)}{ 200.0mm -200.0mm}= \infty$$
The range of object distances is $5.1m\leq d_o\lt\infty$.
