Finding the Fourth Proportional to 12,499.86, 18,755.90 and 5,478.91

Step by Step Solution

1. Step 1: Write the proportion equation
   12,499.86 : 18,755.90 = 5,478.91 : x
2. Step 2: Convert to fraction form
   12,499.86/18,755.90 = 5,478.91/x
3. Step 3: Cross multiply
   12,499.86x = 18,755.90 × 5,478.91
4. Step 4: Simplify right side
   12,499.86x = 102,761,888.07
5. Step 5: Solve for x
   x = 102,761,888.07/12,499.86
6. Step 6: Final answer
   x = 8,221.04