Finding the Fourth Proportional to 1,137.24, 1,569.31 and 639.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.24 : 1,569.31 = 639.83 : x
2. Step 2: Convert to fraction form
   1,137.24/1,569.31 = 639.83/x
3. Step 3: Cross multiply
   1,137.24x = 1,569.31 × 639.83
4. Step 4: Simplify right side
   1,137.24x = 1,004,093.94
5. Step 5: Solve for x
   x = 1,004,093.94/1,137.24
6. Step 6: Final answer
   x = 882.92