Finding the Fourth Proportional to 1,128.42, 1,557.42 and 656.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.42 : 1,557.42 = 656.55 : x
2. Step 2: Convert to fraction form
   1,128.42/1,557.42 = 656.55/x
3. Step 3: Cross multiply
   1,128.42x = 1,557.42 × 656.55
4. Step 4: Simplify right side
   1,128.42x = 1,022,524.10
5. Step 5: Solve for x
   x = 1,022,524.10/1,128.42
6. Step 6: Final answer
   x = 906.16