Finding the Fourth Proportional to 1,103.67, 1,650.72 and 640.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,103.67 : 1,650.72 = 640.32 : x
2. Step 2: Convert to fraction form
   1,103.67/1,650.72 = 640.32/x
3. Step 3: Cross multiply
   1,103.67x = 1,650.72 × 640.32
4. Step 4: Simplify right side
   1,103.67x = 1,056,989.03
5. Step 5: Solve for x
   x = 1,056,989.03/1,103.67
6. Step 6: Final answer
   x = 957.70