Finding the Fourth Proportional to 1,081.52, 1,492.56 and 639.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.52 : 1,492.56 = 639.36 : x
2. Step 2: Convert to fraction form
   1,081.52/1,492.56 = 639.36/x
3. Step 3: Cross multiply
   1,081.52x = 1,492.56 × 639.36
4. Step 4: Simplify right side
   1,081.52x = 954,283.16
5. Step 5: Solve for x
   x = 954,283.16/1,081.52
6. Step 6: Final answer
   x = 882.35