Finding the Fourth Proportional to 21,227.54, 31,774.71 and 13,721.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,227.54 : 31,774.71 = 13,721.10 : x
2. Step 2: Convert to fraction form
   21,227.54/31,774.71 = 13,721.10/x
3. Step 3: Cross multiply
   21,227.54x = 31,774.71 × 13,721.10
4. Step 4: Simplify right side
   21,227.54x = 435,983,905.68
5. Step 5: Solve for x
   x = 435,983,905.68/21,227.54
6. Step 6: Final answer
   x = 20,538.60