Step 1 :To find the increase in population from \( t=1 \) year to \( t=4 \) years, we need to integrate the given growth rate function \( P'(t) \) over the interval from \( t=1 \) to \( t=4 \).
Step 2 :Let \( P'(t) = \sqrt{t}(3370t + 7050) \).
Step 3 :Integrate \( P'(t) \) from \( t=1 \) to \( t=4 \) to find the population increase.
Step 4 :The population increase is \( 74688 \).
Step 5 :Final Answer: \( \boxed{74688} \)