Finding the Fourth Proportional to 1,020.51, 1,408.35 and 578.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.51 : 1,408.35 = 578.43 : x
2. Step 2: Convert to fraction form
   1,020.51/1,408.35 = 578.43/x
3. Step 3: Cross multiply
   1,020.51x = 1,408.35 × 578.43
4. Step 4: Simplify right side
   1,020.51x = 814,631.89
5. Step 5: Solve for x
   x = 814,631.89/1,020.51
6. Step 6: Final answer
   x = 798.26