Finding the Fourth Proportional to 1,081.37, 1,492.30 and 639.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.37 : 1,492.30 = 639.27 : x
2. Step 2: Convert to fraction form
   1,081.37/1,492.30 = 639.27/x
3. Step 3: Cross multiply
   1,081.37x = 1,492.30 × 639.27
4. Step 4: Simplify right side
   1,081.37x = 953,975.16
5. Step 5: Solve for x
   x = 953,975.16/1,081.37
6. Step 6: Final answer
   x = 882.20