Finding the Fourth Proportional to 15,501.80, 21,388.96 and 8,785.89

Step by Step Solution

1. Step 1: Write the proportion equation
   15,501.80 : 21,388.96 = 8,785.89 : x
2. Step 2: Convert to fraction form
   15,501.80/21,388.96 = 8,785.89/x
3. Step 3: Cross multiply
   15,501.80x = 21,388.96 × 8,785.89
4. Step 4: Simplify right side
   15,501.80x = 187,921,049.77
5. Step 5: Solve for x
   x = 187,921,049.77/15,501.80
6. Step 6: Final answer
   x = 12,122.53