Finding the Fourth Proportional to 1,086.83, 1,499.33 and 644.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.83 : 1,499.33 = 644.48 : x
2. Step 2: Convert to fraction form
   1,086.83/1,499.33 = 644.48/x
3. Step 3: Cross multiply
   1,086.83x = 1,499.33 × 644.48
4. Step 4: Simplify right side
   1,086.83x = 966,293.56
5. Step 5: Solve for x
   x = 966,293.56/1,086.83
6. Step 6: Final answer
   x = 889.09