Finding the Fourth Proportional to 12,721.05, 17,555.23 and 7,684.57

Step by Step Solution

1. Step 1: Write the proportion equation
   12,721.05 : 17,555.23 = 7,684.57 : x
2. Step 2: Convert to fraction form
   12,721.05/17,555.23 = 7,684.57/x
3. Step 3: Cross multiply
   12,721.05x = 17,555.23 × 7,684.57
4. Step 4: Simplify right side
   12,721.05x = 134,904,425.35
5. Step 5: Solve for x
   x = 134,904,425.35/12,721.05
6. Step 6: Final answer
   x = 10,604.82