Finding the Fourth Proportional to 21,139.39, 31,684.38 and 10,603.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,139.39 : 31,684.38 = 10,603.72 : x
2. Step 2: Convert to fraction form
   21,139.39/31,684.38 = 10,603.72/x
3. Step 3: Cross multiply
   21,139.39x = 31,684.38 × 10,603.72
4. Step 4: Simplify right side
   21,139.39x = 335,972,293.89
5. Step 5: Solve for x
   x = 335,972,293.89/21,139.39
6. Step 6: Final answer
   x = 15,893.19