Finding the Fourth Proportional to 1,128.54, 1,557.42 and 631.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.54 : 1,557.42 = 631.17 : x
2. Step 2: Convert to fraction form
   1,128.54/1,557.42 = 631.17/x
3. Step 3: Cross multiply
   1,128.54x = 1,557.42 × 631.17
4. Step 4: Simplify right side
   1,128.54x = 982,996.78
5. Step 5: Solve for x
   x = 982,996.78/1,128.54
6. Step 6: Final answer
   x = 871.03