Finding the Fourth Proportional to 1,137.55, 1,569.86 and 640.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.55 : 1,569.86 = 640.17 : x
2. Step 2: Convert to fraction form
   1,137.55/1,569.86 = 640.17/x
3. Step 3: Cross multiply
   1,137.55x = 1,569.86 × 640.17
4. Step 4: Simplify right side
   1,137.55x = 1,004,977.28
5. Step 5: Solve for x
   x = 1,004,977.28/1,137.55
6. Step 6: Final answer
   x = 883.46