Finding the Fourth Proportional to 1,298.40, 1,792 and 774.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.40 : 1,792 = 774.56 : x
2. Step 2: Convert to fraction form
   1,298.40/1,792 = 774.56/x
3. Step 3: Cross multiply
   1,298.40x = 1,792 × 774.56
4. Step 4: Simplify right side
   1,298.40x = 1,388,011.52
5. Step 5: Solve for x
   x = 1,388,011.52/1,298.40
6. Step 6: Final answer
   x = 1,069.02