Finding the Fourth Proportional to 388,871.72, 536,659.52 and 216,789.65

Step by Step Solution

1. Step 1: Write the proportion equation
   388,871.72 : 536,659.52 = 216,789.65 : x
2. Step 2: Convert to fraction form
   388,871.72/536,659.52 = 216,789.65/x
3. Step 3: Cross multiply
   388,871.72x = 536,659.52 × 216,789.65
4. Step 4: Simplify right side
   388,871.72x = 116,342,225,742.72
5. Step 5: Solve for x
   x = 116,342,225,742.72/388,871.72
6. Step 6: Final answer
   x = 299,178.94