Finding the Fourth Proportional to 1,137.37, 1,569.45 and 639.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.37 : 1,569.45 = 639.96 : x
2. Step 2: Convert to fraction form
   1,137.37/1,569.45 = 639.96/x
3. Step 3: Cross multiply
   1,137.37x = 1,569.45 × 639.96
4. Step 4: Simplify right side
   1,137.37x = 1,004,377.37
5. Step 5: Solve for x
   x = 1,004,377.37/1,137.37
6. Step 6: Final answer
   x = 883.07