Finding the Fourth Proportional to 518,667.48, 715,773.81 and 289,222.55

Step by Step Solution

1. Step 1: Write the proportion equation
   518,667.48 : 715,773.81 = 289,222.55 : x
2. Step 2: Convert to fraction form
   518,667.48/715,773.81 = 289,222.55/x
3. Step 3: Cross multiply
   518,667.48x = 715,773.81 × 289,222.55
4. Step 4: Simplify right side
   518,667.48x = 207,017,926,741.28
5. Step 5: Solve for x
   x = 207,017,926,741.28/518,667.48
6. Step 6: Final answer
   x = 399,134.20