Finding the Fourth Proportional to 1,137.52, 1,569.72 and 640.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.52 : 1,569.72 = 640.15 : x
2. Step 2: Convert to fraction form
   1,137.52/1,569.72 = 640.15/x
3. Step 3: Cross multiply
   1,137.52x = 1,569.72 × 640.15
4. Step 4: Simplify right side
   1,137.52x = 1,004,856.26
5. Step 5: Solve for x
   x = 1,004,856.26/1,137.52
6. Step 6: Final answer
   x = 883.37