Finding the Fourth Proportional to 1,020.92, 1,408.82 and 578.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.92 : 1,408.82 = 578.81 : x
2. Step 2: Convert to fraction form
   1,020.92/1,408.82 = 578.81/x
3. Step 3: Cross multiply
   1,020.92x = 1,408.82 × 578.81
4. Step 4: Simplify right side
   1,020.92x = 815,429.17
5. Step 5: Solve for x
   x = 815,429.17/1,020.92
6. Step 6: Final answer
   x = 798.72