Finding the Fourth Proportional to 15,499.71, 21,388.89 and 8,785.19

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.71 : 21,388.89 = 8,785.19 : x
2. Step 2: Convert to fraction form
   15,499.71/21,388.89 = 8,785.19/x
3. Step 3: Cross multiply
   15,499.71x = 21,388.89 × 8,785.19
4. Step 4: Simplify right side
   15,499.71x = 187,905,355.59
5. Step 5: Solve for x
   x = 187,905,355.59/15,499.71
6. Step 6: Final answer
   x = 12,123.15