Finding the Fourth Proportional to 21,671.55, 29,906.28 and 12,111.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,671.55 : 29,906.28 = 12,111.53 : x
2. Step 2: Convert to fraction form
   21,671.55/29,906.28 = 12,111.53/x
3. Step 3: Cross multiply
   21,671.55x = 29,906.28 × 12,111.53
4. Step 4: Simplify right side
   21,671.55x = 362,210,657.88
5. Step 5: Solve for x
   x = 362,210,657.88/21,671.55
6. Step 6: Final answer
   x = 16,713.65