Finding the Fourth Proportional to 1,139.50, 1,571.88 and 765.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.50 : 1,571.88 = 765.82 : x
2. Step 2: Convert to fraction form
   1,139.50/1,571.88 = 765.82/x
3. Step 3: Cross multiply
   1,139.50x = 1,571.88 × 765.82
4. Step 4: Simplify right side
   1,139.50x = 1,203,777.14
5. Step 5: Solve for x
   x = 1,203,777.14/1,139.50
6. Step 6: Final answer
   x = 1,056.41