Finding the Fourth Proportional to 518,965, 716,171.78 and 280,501

Step by Step Solution

1. Step 1: Write the proportion equation
   518,965 : 716,171.78 = 280,501 : x
2. Step 2: Convert to fraction form
   518,965/716,171.78 = 280,501/x
3. Step 3: Cross multiply
   518,965x = 716,171.78 × 280,501
4. Step 4: Simplify right side
   518,965x = 200,886,900,461.78
5. Step 5: Solve for x
   x = 200,886,900,461.78/518,965
6. Step 6: Final answer
   x = 387,091.42