Finding the Fourth Proportional to 505,111.60, 697,070.28 and 287,314.69

Step by Step Solution

1. Step 1: Write the proportion equation
   505,111.60 : 697,070.28 = 287,314.69 : x
2. Step 2: Convert to fraction form
   505,111.60/697,070.28 = 287,314.69/x
3. Step 3: Cross multiply
   505,111.60x = 697,070.28 × 287,314.69
4. Step 4: Simplify right side
   505,111.60x = 200,278,531,406.41
5. Step 5: Solve for x
   x = 200,278,531,406.41/505,111.60
6. Step 6: Final answer
   x = 396,503.53