Finding the Fourth Proportional to 1,081.58, 1,492.17 and 639.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.58 : 1,492.17 = 639.32 : x
2. Step 2: Convert to fraction form
   1,081.58/1,492.17 = 639.32/x
3. Step 3: Cross multiply
   1,081.58x = 1,492.17 × 639.32
4. Step 4: Simplify right side
   1,081.58x = 953,974.12
5. Step 5: Solve for x
   x = 953,974.12/1,081.58
6. Step 6: Final answer
   x = 882.02