Finding the Fourth Proportional to 1,168.55, 1,612.58 and 644.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.55 : 1,612.58 = 644.57 : x
2. Step 2: Convert to fraction form
   1,168.55/1,612.58 = 644.57/x
3. Step 3: Cross multiply
   1,168.55x = 1,612.58 × 644.57
4. Step 4: Simplify right side
   1,168.55x = 1,039,420.69
5. Step 5: Solve for x
   x = 1,039,420.69/1,168.55
6. Step 6: Final answer
   x = 889.50