Finding the Fourth Proportional to 1,296.78, 1,789.59 and 765.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,296.78 : 1,789.59 = 765.69 : x
2. Step 2: Convert to fraction form
   1,296.78/1,789.59 = 765.69/x
3. Step 3: Cross multiply
   1,296.78x = 1,789.59 × 765.69
4. Step 4: Simplify right side
   1,296.78x = 1,370,271.17
5. Step 5: Solve for x
   x = 1,370,271.17/1,296.78
6. Step 6: Final answer
   x = 1,056.67