Step 1 :Convert days to weeks: Day 15 is equivalent to \( \frac{15}{7} \) weeks and day 28 is equivalent to \( \frac{28}{7} \) weeks
Step 2 :Calculate the definite integral of the rate function from \( \frac{15}{7} \) to \( \frac{28}{7} \) to find the total number of bicycles produced
Step 3 :Round down the result to the nearest whole number since a factory only produces whole bicycles
Step 4 :The total number of bicycles produced from day 15 to day 28 is \(\boxed{198}\) bicycles