Finding the Fourth Proportional to 1,020.69, 1,408.22 and 572.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.69 : 1,408.22 = 572.50 : x
2. Step 2: Convert to fraction form
   1,020.69/1,408.22 = 572.50/x
3. Step 3: Cross multiply
   1,020.69x = 1,408.22 × 572.50
4. Step 4: Simplify right side
   1,020.69x = 806,203.86
5. Step 5: Solve for x
   x = 806,203.86/1,020.69
6. Step 6: Final answer
   x = 789.86