Answer:
3.11%
Step-by-step explanation:
We express a solution's volume by volume percent concentration, % v/v,
Take the ratio of the isopropyl alcohol (IPA) volume to the total volume of the solution, which is 1400 mL of water+ 45 mL of IPA,
and multiply by 100 to get the percentage: 45/(1400+45) *100 = 0.0311*100 = 3.11%