Finding the Fourth Proportional to 1,168.53, 1,612.55 and 644.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.53 : 1,612.55 = 644.56 : x
2. Step 2: Convert to fraction form
   1,168.53/1,612.55 = 644.56/x
3. Step 3: Cross multiply
   1,168.53x = 1,612.55 × 644.56
4. Step 4: Simplify right side
   1,168.53x = 1,039,382.01
5. Step 5: Solve for x
   x = 1,039,382.01/1,168.53
6. Step 6: Final answer
   x = 889.48