Finding the Fourth Proportional to 1,355.20, 2,028.72 and 866.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.20 : 2,028.72 = 866.56 : x
2. Step 2: Convert to fraction form
   1,355.20/2,028.72 = 866.56/x
3. Step 3: Cross multiply
   1,355.20x = 2,028.72 × 866.56
4. Step 4: Simplify right side
   1,355.20x = 1,758,007.60
5. Step 5: Solve for x
   x = 1,758,007.60/1,355.20
6. Step 6: Final answer
   x = 1,297.23