Finding the Fourth Proportional to 1,092.54, 1,507.72 and 644.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,092.54 : 1,507.72 = 644.72 : x
2. Step 2: Convert to fraction form
   1,092.54/1,507.72 = 644.72/x
3. Step 3: Cross multiply
   1,092.54x = 1,507.72 × 644.72
4. Step 4: Simplify right side
   1,092.54x = 972,057.24
5. Step 5: Solve for x
   x = 972,057.24/1,092.54
6. Step 6: Final answer
   x = 889.72