Finding the Fourth Proportional to 13,139.50, 19,712.52 and 3,905.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.50 : 19,712.52 = 3,905.50 : x
2. Step 2: Convert to fraction form
   13,139.50/19,712.52 = 3,905.50/x
3. Step 3: Cross multiply
   13,139.50x = 19,712.52 × 3,905.50
4. Step 4: Simplify right side
   13,139.50x = 76,987,246.86
5. Step 5: Solve for x
   x = 76,987,246.86/13,139.50
6. Step 6: Final answer
   x = 5,859.22