Finding the Fourth Proportional to 1,020.18, 1,407.85 and 554.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.18 : 1,407.85 = 554.43 : x
2. Step 2: Convert to fraction form
   1,020.18/1,407.85 = 554.43/x
3. Step 3: Cross multiply
   1,020.18x = 1,407.85 × 554.43
4. Step 4: Simplify right side
   1,020.18x = 780,552.89
5. Step 5: Solve for x
   x = 780,552.89/1,020.18
6. Step 6: Final answer
   x = 765.11