Finding the Fourth Proportional to 13,140.84, 19,710.78 and 3,906.60

Step by Step Solution

1. Step 1: Write the proportion equation
   13,140.84 : 19,710.78 = 3,906.60 : x
2. Step 2: Convert to fraction form
   13,140.84/19,710.78 = 3,906.60/x
3. Step 3: Cross multiply
   13,140.84x = 19,710.78 × 3,906.60
4. Step 4: Simplify right side
   13,140.84x = 77,002,133.15
5. Step 5: Solve for x
   x = 77,002,133.15/13,140.84
6. Step 6: Final answer
   x = 5,859.76