Finding the Fourth Proportional to 1,285.31, 1,927.83 and 505.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,285.31 : 1,927.83 = 505.15 : x
2. Step 2: Convert to fraction form
   1,285.31/1,927.83 = 505.15/x
3. Step 3: Cross multiply
   1,285.31x = 1,927.83 × 505.15
4. Step 4: Simplify right side
   1,285.31x = 973,843.32
5. Step 5: Solve for x
   x = 973,843.32/1,285.31
6. Step 6: Final answer
   x = 757.67