If monthly sales increased from 19.35 to 23.32 what is the percentage of increase?

To calculate the percentage increase, subtract the original value from the new value, then divide by the original value and multiply by 100. The calculation is as follows: ((23.32 - 19.35) / 19.35 \times 100), which equals approximately 20.45%. Therefore, the percentage increase in monthly sales is about 20.45%.