Finding the Fourth Proportional to 1,296.81, 1,789.61 and 772.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,296.81 : 1,789.61 = 772.74 : x
2. Step 2: Convert to fraction form
   1,296.81/1,789.61 = 772.74/x
3. Step 3: Cross multiply
   1,296.81x = 1,789.61 × 772.74
4. Step 4: Simplify right side
   1,296.81x = 1,382,899.37
5. Step 5: Solve for x
   x = 1,382,899.37/1,296.81
6. Step 6: Final answer
   x = 1,066.39