Finding the Fourth Proportional to 1,128.73, 1,557.74 and 631.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.73 : 1,557.74 = 631.46 : x
2. Step 2: Convert to fraction form
   1,128.73/1,557.74 = 631.46/x
3. Step 3: Cross multiply
   1,128.73x = 1,557.74 × 631.46
4. Step 4: Simplify right side
   1,128.73x = 983,650.50
5. Step 5: Solve for x
   x = 983,650.50/1,128.73
6. Step 6: Final answer
   x = 871.47