Finding the Fourth Proportional to 1,013.84, 1,399.12 and 571.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.84 : 1,399.12 = 571.80 : x
2. Step 2: Convert to fraction form
   1,013.84/1,399.12 = 571.80/x
3. Step 3: Cross multiply
   1,013.84x = 1,399.12 × 571.80
4. Step 4: Simplify right side
   1,013.84x = 800,016.82
5. Step 5: Solve for x
   x = 800,016.82/1,013.84
6. Step 6: Final answer
   x = 789.10