Finding the Fourth Proportional to 1,020.47, 1,408.25 and 554.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.47 : 1,408.25 = 554.72 : x
2. Step 2: Convert to fraction form
   1,020.47/1,408.25 = 554.72/x
3. Step 3: Cross multiply
   1,020.47x = 1,408.25 × 554.72
4. Step 4: Simplify right side
   1,020.47x = 781,189.35
5. Step 5: Solve for x
   x = 781,189.35/1,020.47
6. Step 6: Final answer
   x = 765.52