Finding the Fourth Proportional to 1,008.72, 1,391.46 and 635.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.72 : 1,391.46 = 635.56 : x
2. Step 2: Convert to fraction form
   1,008.72/1,391.46 = 635.56/x
3. Step 3: Cross multiply
   1,008.72x = 1,391.46 × 635.56
4. Step 4: Simplify right side
   1,008.72x = 884,361.86
5. Step 5: Solve for x
   x = 884,361.86/1,008.72
6. Step 6: Final answer
   x = 876.72