Finding the Fourth Proportional to 1,019.53, 1,406.97 and 553.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.53 : 1,406.97 = 553.78 : x
2. Step 2: Convert to fraction form
   1,019.53/1,406.97 = 553.78/x
3. Step 3: Cross multiply
   1,019.53x = 1,406.97 × 553.78
4. Step 4: Simplify right side
   1,019.53x = 779,153.61
5. Step 5: Solve for x
   x = 779,153.61/1,019.53
6. Step 6: Final answer
   x = 764.23