Finding the Fourth Proportional to 1,042.72, 1,438.24 and 649.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,042.72 : 1,438.24 = 649.60 : x
2. Step 2: Convert to fraction form
   1,042.72/1,438.24 = 649.60/x
3. Step 3: Cross multiply
   1,042.72x = 1,438.24 × 649.60
4. Step 4: Simplify right side
   1,042.72x = 934,280.70
5. Step 5: Solve for x
   x = 934,280.70/1,042.72
6. Step 6: Final answer
   x = 896.00