Finding the Fourth Proportional to 1,141.48, 1,575.20 and 644.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.48 : 1,575.20 = 644.10 : x
2. Step 2: Convert to fraction form
   1,141.48/1,575.20 = 644.10/x
3. Step 3: Cross multiply
   1,141.48x = 1,575.20 × 644.10
4. Step 4: Simplify right side
   1,141.48x = 1,014,586.32
5. Step 5: Solve for x
   x = 1,014,586.32/1,141.48
6. Step 6: Final answer
   x = 888.83