Finding the Fourth Proportional to 1,019.50, 1,406.94 and 553.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.50 : 1,406.94 = 553.78 : x
2. Step 2: Convert to fraction form
   1,019.50/1,406.94 = 553.78/x
3. Step 3: Cross multiply
   1,019.50x = 1,406.94 × 553.78
4. Step 4: Simplify right side
   1,019.50x = 779,135.23
5. Step 5: Solve for x
   x = 779,135.23/1,019.50
6. Step 6: Final answer
   x = 764.23