Finding the Fourth Proportional to 1,018.98, 1,406.18 and 553.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.98 : 1,406.18 = 553.23 : x
2. Step 2: Convert to fraction form
   1,018.98/1,406.18 = 553.23/x
3. Step 3: Cross multiply
   1,018.98x = 1,406.18 × 553.23
4. Step 4: Simplify right side
   1,018.98x = 777,938.20
5. Step 5: Solve for x
   x = 777,938.20/1,018.98
6. Step 6: Final answer
   x = 763.45