Finding the Fourth Proportional to 1,013.69, 1,398.85 and 571.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.69 : 1,398.85 = 571.57 : x
2. Step 2: Convert to fraction form
   1,013.69/1,398.85 = 571.57/x
3. Step 3: Cross multiply
   1,013.69x = 1,398.85 × 571.57
4. Step 4: Simplify right side
   1,013.69x = 799,535.77
5. Step 5: Solve for x
   x = 799,535.77/1,013.69
6. Step 6: Final answer
   x = 788.74