Finding the Fourth Proportional to 1,018.50, 1,405.56 and 552.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.50 : 1,405.56 = 552.78 : x
2. Step 2: Convert to fraction form
   1,018.50/1,405.56 = 552.78/x
3. Step 3: Cross multiply
   1,018.50x = 1,405.56 × 552.78
4. Step 4: Simplify right side
   1,018.50x = 776,965.46
5. Step 5: Solve for x
   x = 776,965.46/1,018.50
6. Step 6: Final answer
   x = 762.85