Finding the Fourth Proportional to 1,141.83, 1,575.82 and 644.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.83 : 1,575.82 = 644.57 : x
2. Step 2: Convert to fraction form
   1,141.83/1,575.82 = 644.57/x
3. Step 3: Cross multiply
   1,141.83x = 1,575.82 × 644.57
4. Step 4: Simplify right side
   1,141.83x = 1,015,726.30
5. Step 5: Solve for x
   x = 1,015,726.30/1,141.83
6. Step 6: Final answer
   x = 889.56