Finding the Fourth Proportional to 21,681.09, 29,913.89 and 13,726.71

Step by Step Solution

1. Step 1: Write the proportion equation
   21,681.09 : 29,913.89 = 13,726.71 : x
2. Step 2: Convert to fraction form
   21,681.09/29,913.89 = 13,726.71/x
3. Step 3: Cross multiply
   21,681.09x = 29,913.89 × 13,726.71
4. Step 4: Simplify right side
   21,681.09x = 410,619,224.37
5. Step 5: Solve for x
   x = 410,619,224.37/21,681.09
6. Step 6: Final answer
   x = 18,939.05