Finding the Fourth Proportional to 1,128.95, 1,557.98 and 631.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.95 : 1,557.98 = 631.59 : x
2. Step 2: Convert to fraction form
   1,128.95/1,557.98 = 631.59/x
3. Step 3: Cross multiply
   1,128.95x = 1,557.98 × 631.59
4. Step 4: Simplify right side
   1,128.95x = 984,001.43
5. Step 5: Solve for x
   x = 984,001.43/1,128.95
6. Step 6: Final answer
   x = 871.61