Finding the Fourth Proportional to 1,296.38, 1,788.89 and 772.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,296.38 : 1,788.89 = 772.31 : x
2. Step 2: Convert to fraction form
   1,296.38/1,788.89 = 772.31/x
3. Step 3: Cross multiply
   1,296.38x = 1,788.89 × 772.31
4. Step 4: Simplify right side
   1,296.38x = 1,381,578.25
5. Step 5: Solve for x
   x = 1,381,578.25/1,296.38
6. Step 6: Final answer
   x = 1,065.72