Finding the Fourth Proportional to 355,585.31, 490,667.42 and 210,395.55

Step by Step Solution

1. Step 1: Write the proportion equation
   355,585.31 : 490,667.42 = 210,395.55 : x
2. Step 2: Convert to fraction form
   355,585.31/490,667.42 = 210,395.55/x
3. Step 3: Cross multiply
   355,585.31x = 490,667.42 × 210,395.55
4. Step 4: Simplify right side
   355,585.31x = 103,234,241,697.98
5. Step 5: Solve for x
   x = 103,234,241,697.98/355,585.31
6. Step 6: Final answer
   x = 290,322.01