Finding the Fourth Proportional to 1,168.68, 1,612.83 and 644.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.68 : 1,612.83 = 644.76 : x
2. Step 2: Convert to fraction form
   1,168.68/1,612.83 = 644.76/x
3. Step 3: Cross multiply
   1,168.68x = 1,612.83 × 644.76
4. Step 4: Simplify right side
   1,168.68x = 1,039,888.27
5. Step 5: Solve for x
   x = 1,039,888.27/1,168.68
6. Step 6: Final answer
   x = 889.80