Finding the Fourth Proportional to 1,285.50, 1,931.85 and 765.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,285.50 : 1,931.85 = 765.59 : x
2. Step 2: Convert to fraction form
   1,285.50/1,931.85 = 765.59/x
3. Step 3: Cross multiply
   1,285.50x = 1,931.85 × 765.59
4. Step 4: Simplify right side
   1,285.50x = 1,478,995.38
5. Step 5: Solve for x
   x = 1,478,995.38/1,285.50
6. Step 6: Final answer
   x = 1,150.52