Finding the Fourth Proportional to 21,856.72, 30,166.18 and 12,903.68

Step by Step Solution

1. Step 1: Write the proportion equation
   21,856.72 : 30,166.18 = 12,903.68 : x
2. Step 2: Convert to fraction form
   21,856.72/30,166.18 = 12,903.68/x
3. Step 3: Cross multiply
   21,856.72x = 30,166.18 × 12,903.68
4. Step 4: Simplify right side
   21,856.72x = 389,254,733.54
5. Step 5: Solve for x
   x = 389,254,733.54/21,856.72
6. Step 6: Final answer
   x = 17,809.38