Finding the Fourth Proportional to 21,635.03, 29,856.72 and 12,688.98

Step by Step Solution

1. Step 1: Write the proportion equation
   21,635.03 : 29,856.72 = 12,688.98 : x
2. Step 2: Convert to fraction form
   21,635.03/29,856.72 = 12,688.98/x
3. Step 3: Cross multiply
   21,635.03x = 29,856.72 × 12,688.98
4. Step 4: Simplify right side
   21,635.03x = 378,851,322.95
5. Step 5: Solve for x
   x = 378,851,322.95/21,635.03
6. Step 6: Final answer
   x = 17,511.02