Finding the Fourth Proportional to 1,128.59, 1,557.29 and 631.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.59 : 1,557.29 = 631.18 : x
2. Step 2: Convert to fraction form
   1,128.59/1,557.29 = 631.18/x
3. Step 3: Cross multiply
   1,128.59x = 1,557.29 × 631.18
4. Step 4: Simplify right side
   1,128.59x = 982,930.30
5. Step 5: Solve for x
   x = 982,930.30/1,128.59
6. Step 6: Final answer
   x = 870.94