Finding the Fourth Proportional to 1,131.15, 1,695.31 and 644.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.15 : 1,695.31 = 644.48 : x
2. Step 2: Convert to fraction form
   1,131.15/1,695.31 = 644.48/x
3. Step 3: Cross multiply
   1,131.15x = 1,695.31 × 644.48
4. Step 4: Simplify right side
   1,131.15x = 1,092,581.69
5. Step 5: Solve for x
   x = 1,092,581.69/1,131.15
6. Step 6: Final answer
   x = 965.90