Finding the Fourth Proportional to 137,139.69, 205,729.20 and 42,378.15

Step by Step Solution

1. Step 1: Write the proportion equation
   137,139.69 : 205,729.20 = 42,378.15 : x
2. Step 2: Convert to fraction form
   137,139.69/205,729.20 = 42,378.15/x
3. Step 3: Cross multiply
   137,139.69x = 205,729.20 × 42,378.15
4. Step 4: Simplify right side
   137,139.69x = 8,718,423,668.46
5. Step 5: Solve for x
   x = 8,718,423,668.46/137,139.69
6. Step 6: Final answer
   x = 63,573.31