Finding the Fourth Proportional to 1,141.72, 1,575.73 and 644.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.72 : 1,575.73 = 644.56 : x
2. Step 2: Convert to fraction form
   1,141.72/1,575.73 = 644.56/x
3. Step 3: Cross multiply
   1,141.72x = 1,575.73 × 644.56
4. Step 4: Simplify right side
   1,141.72x = 1,015,652.53
5. Step 5: Solve for x
   x = 1,015,652.53/1,141.72
6. Step 6: Final answer
   x = 889.58