Finding the Fourth Proportional to 139,642.80, 209,472.30 and 39,810.30

Step by Step Solution

1. Step 1: Write the proportion equation
   139,642.80 : 209,472.30 = 39,810.30 : x
2. Step 2: Convert to fraction form
   139,642.80/209,472.30 = 39,810.30/x
3. Step 3: Cross multiply
   139,642.80x = 209,472.30 × 39,810.30
4. Step 4: Simplify right side
   139,642.80x = 8,339,155,104.69
5. Step 5: Solve for x
   x = 8,339,155,104.69/139,642.80
6. Step 6: Final answer
   x = 59,717.76