Finding the Fourth Proportional to 388,458.52, 536,082.78 and 218,698.72

Step by Step Solution

1. Step 1: Write the proportion equation
   388,458.52 : 536,082.78 = 218,698.72 : x
2. Step 2: Convert to fraction form
   388,458.52/536,082.78 = 218,698.72/x
3. Step 3: Cross multiply
   388,458.52x = 536,082.78 × 218,698.72
4. Step 4: Simplify right side
   388,458.52x = 117,240,617,800.04
5. Step 5: Solve for x
   x = 117,240,617,800.04/388,458.52
6. Step 6: Final answer
   x = 301,809.88