Finding the Fourth Proportional to 1,020.72, 1,408.59 and 554.97

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.72 : 1,408.59 = 554.97 : x
2. Step 2: Convert to fraction form
   1,020.72/1,408.59 = 554.97/x
3. Step 3: Cross multiply
   1,020.72x = 1,408.59 × 554.97
4. Step 4: Simplify right side
   1,020.72x = 781,725.19
5. Step 5: Solve for x
   x = 781,725.19/1,020.72
6. Step 6: Final answer
   x = 765.86