Finding the Fourth Proportional to 13,887.64, 20,831.59 and 3,499.39

Step by Step Solution

1. Step 1: Write the proportion equation
   13,887.64 : 20,831.59 = 3,499.39 : x
2. Step 2: Convert to fraction form
   13,887.64/20,831.59 = 3,499.39/x
3. Step 3: Cross multiply
   13,887.64x = 20,831.59 × 3,499.39
4. Step 4: Simplify right side
   13,887.64x = 72,897,744.82
5. Step 5: Solve for x
   x = 72,897,744.82/13,887.64
6. Step 6: Final answer
   x = 5,249.11