Finding the Fourth Proportional to 1,385.17, 1,911.55 and 755.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.17 : 1,911.55 = 755.70 : x
2. Step 2: Convert to fraction form
   1,385.17/1,911.55 = 755.70/x
3. Step 3: Cross multiply
   1,385.17x = 1,911.55 × 755.70
4. Step 4: Simplify right side
   1,385.17x = 1,444,563.61
5. Step 5: Solve for x
   x = 1,444,563.61/1,385.17
6. Step 6: Final answer
   x = 1,042.88