Finding the Fourth Proportional to 1,020.94, 1,408.89 and 578.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.94 : 1,408.89 = 578.83 : x
2. Step 2: Convert to fraction form
   1,020.94/1,408.89 = 578.83/x
3. Step 3: Cross multiply
   1,020.94x = 1,408.89 × 578.83
4. Step 4: Simplify right side
   1,020.94x = 815,507.80
5. Step 5: Solve for x
   x = 815,507.80/1,020.94
6. Step 6: Final answer
   x = 798.78