Finding the Fourth Proportional to 1,012.82, 1,397.69 and 570.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.82 : 1,397.69 = 570.80 : x
2. Step 2: Convert to fraction form
   1,012.82/1,397.69 = 570.80/x
3. Step 3: Cross multiply
   1,012.82x = 1,397.69 × 570.80
4. Step 4: Simplify right side
   1,012.82x = 797,804.01
5. Step 5: Solve for x
   x = 797,804.01/1,012.82
6. Step 6: Final answer
   x = 787.71