Finding the Fourth Proportional to 15,499.43, 21,388.77 and 8,785.68

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.43 : 21,388.77 = 8,785.68 : x
2. Step 2: Convert to fraction form
   15,499.43/21,388.77 = 8,785.68/x
3. Step 3: Cross multiply
   15,499.43x = 21,388.77 × 8,785.68
4. Step 4: Simplify right side
   15,499.43x = 187,914,888.81
5. Step 5: Solve for x
   x = 187,914,888.81/15,499.43
6. Step 6: Final answer
   x = 12,123.99