Finding the Fourth Proportional to 1,128.92, 1,557.72 and 631.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.92 : 1,557.72 = 631.54 : x
2. Step 2: Convert to fraction form
   1,128.92/1,557.72 = 631.54/x
3. Step 3: Cross multiply
   1,128.92x = 1,557.72 × 631.54
4. Step 4: Simplify right side
   1,128.92x = 983,762.49
5. Step 5: Solve for x
   x = 983,762.49/1,128.92
6. Step 6: Final answer
   x = 871.42