Finding the Fourth Proportional to 1,168.62, 1,612.71 and 644.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.62 : 1,612.71 = 644.64 : x
2. Step 2: Convert to fraction form
   1,168.62/1,612.71 = 644.64/x
3. Step 3: Cross multiply
   1,168.62x = 1,612.71 × 644.64
4. Step 4: Simplify right side
   1,168.62x = 1,039,617.37
5. Step 5: Solve for x
   x = 1,039,617.37/1,168.62
6. Step 6: Final answer
   x = 889.61