Finding the Fourth Proportional to 1,137.56, 1,569.78 and 640.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.56 : 1,569.78 = 640.22 : x
2. Step 2: Convert to fraction form
   1,137.56/1,569.78 = 640.22/x
3. Step 3: Cross multiply
   1,137.56x = 1,569.78 × 640.22
4. Step 4: Simplify right side
   1,137.56x = 1,005,004.55
5. Step 5: Solve for x
   x = 1,005,004.55/1,137.56
6. Step 6: Final answer
   x = 883.47