Finding the Fourth Proportional to 1,398.96, 1,930.57 and 769.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.96 : 1,930.57 = 769.55 : x
2. Step 2: Convert to fraction form
   1,398.96/1,930.57 = 769.55/x
3. Step 3: Cross multiply
   1,398.96x = 1,930.57 × 769.55
4. Step 4: Simplify right side
   1,398.96x = 1,485,674.01
5. Step 5: Solve for x
   x = 1,485,674.01/1,398.96
6. Step 6: Final answer
   x = 1,061.98