You receive a prescription calling for 12% nystatin cream to be compounded. You have 15 grams of a 35% cream on hand as well as a 2% cream. Using the alligation method, how many grams of 2% cream should be added to the whole amount of 35% cream to prepare the final product? Round to the nearest tenth decimal place.

Here's how to solve this compounding problem using the alligation method: **Understanding the Problem** * You need to make a 12% nystatin cream. * You have a 35% nystatin cream and a 2% nystatin cream. * You'll be using all 15 grams of the stronger 35% cream. **Alligation Method** 1. **Set up the table:** | Concentration | Desired Concentration | Difference | |---|---|---| | 35% | 12% | 23 | | 2% | 12% | 10 | 2. **Interpret the differences:** * To get the desired 12%, you need 10 parts of the 2% cream for every 23 parts of the 35% cream. 3. **Calculate the ratio:** * Ratio = (Low concentration - Desired concentration) / (Desired concentration - High concentration) * Ratio = (2 - 12) / (12 - 35) = 10 / 23 4. **Calculate the amount of 2% cream:** * Total amount = 15 grams of 35% cream * Amount of 2% cream = (Ratio * Total amount) = (10/23) * 15 grams = 6.5 grams (approximately) **Answer:** You need to add approximately 6.5 grams of the 2% nystatin cream to the 15 grams of 35% cream to create the desired 12% concentration.