Finding the Fourth Proportional to 21,641.07, 29,856.89 and 13,146.70

Step by Step Solution

1. Step 1: Write the proportion equation
   21,641.07 : 29,856.89 = 13,146.70 : x
2. Step 2: Convert to fraction form
   21,641.07/29,856.89 = 13,146.70/x
3. Step 3: Cross multiply
   21,641.07x = 29,856.89 × 13,146.70
4. Step 4: Simplify right side
   21,641.07x = 392,519,510.03
5. Step 5: Solve for x
   x = 392,519,510.03/21,641.07
6. Step 6: Final answer
   x = 18,137.71