Finding the Fourth Proportional to 7,680.72, 11,509.34 and 5,172.62

Step by Step Solution

1. Step 1: Write the proportion equation
   7,680.72 : 11,509.34 = 5,172.62 : x
2. Step 2: Convert to fraction form
   7,680.72/11,509.34 = 5,172.62/x
3. Step 3: Cross multiply
   7,680.72x = 11,509.34 × 5,172.62
4. Step 4: Simplify right side
   7,680.72x = 59,533,442.27
5. Step 5: Solve for x
   x = 59,533,442.27/7,680.72
6. Step 6: Final answer
   x = 7,751.02