Finding the Fourth Proportional to 1,081.88, 1,492.82 and 639.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.88 : 1,492.82 = 639.62 : x
2. Step 2: Convert to fraction form
   1,081.88/1,492.82 = 639.62/x
3. Step 3: Cross multiply
   1,081.88x = 1,492.82 × 639.62
4. Step 4: Simplify right side
   1,081.88x = 954,837.53
5. Step 5: Solve for x
   x = 954,837.53/1,081.88
6. Step 6: Final answer
   x = 882.57