Finding the Fourth Proportional to 1,012.15, 1,396.76 and 570.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.15 : 1,396.76 = 570.20 : x
2. Step 2: Convert to fraction form
   1,012.15/1,396.76 = 570.20/x
3. Step 3: Cross multiply
   1,012.15x = 1,396.76 × 570.20
4. Step 4: Simplify right side
   1,012.15x = 796,429.45
5. Step 5: Solve for x
   x = 796,429.45/1,012.15
6. Step 6: Final answer
   x = 786.87