Finding the Fourth Proportional to 1,013.77, 1,399.00 and 571.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.77 : 1,399.00 = 571.81 : x
2. Step 2: Convert to fraction form
   1,013.77/1,399.00 = 571.81/x
3. Step 3: Cross multiply
   1,013.77x = 1,399.00 × 571.81
4. Step 4: Simplify right side
   1,013.77x = 799,959.35
5. Step 5: Solve for x
   x = 799,959.35/1,013.77
6. Step 6: Final answer
   x = 789.10