Finding the Fourth Proportional to 1,081.73, 1,492.72 and 639.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.73 : 1,492.72 = 639.54 : x
2. Step 2: Convert to fraction form
   1,081.73/1,492.72 = 639.54/x
3. Step 3: Cross multiply
   1,081.73x = 1,492.72 × 639.54
4. Step 4: Simplify right side
   1,081.73x = 954,652.55
5. Step 5: Solve for x
   x = 954,652.55/1,081.73
6. Step 6: Final answer
   x = 882.52