Finding the Fourth Proportional to 505,111.12, 697,069.62 and 287,314.16

Step by Step Solution

1. Step 1: Write the proportion equation
   505,111.12 : 697,069.62 = 287,314.16 : x
2. Step 2: Convert to fraction form
   505,111.12/697,069.62 = 287,314.16/x
3. Step 3: Cross multiply
   505,111.12x = 697,069.62 × 287,314.16
4. Step 4: Simplify right side
   505,111.12x = 200,277,972,331.82
5. Step 5: Solve for x
   x = 200,277,972,331.82/505,111.12
6. Step 6: Final answer
   x = 396,502.80