Finding the Fourth Proportional to 1,012.20, 1,396.84 and 570.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.20 : 1,396.84 = 570.06 : x
2. Step 2: Convert to fraction form
   1,012.20/1,396.84 = 570.06/x
3. Step 3: Cross multiply
   1,012.20x = 1,396.84 × 570.06
4. Step 4: Simplify right side
   1,012.20x = 796,282.61
5. Step 5: Solve for x
   x = 796,282.61/1,012.20
6. Step 6: Final answer
   x = 786.69