Finding the Fourth Proportional to 1,032.72, 1,549.72 and 643.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,032.72 : 1,549.72 = 643.49 : x
2. Step 2: Convert to fraction form
   1,032.72/1,549.72 = 643.49/x
3. Step 3: Cross multiply
   1,032.72x = 1,549.72 × 643.49
4. Step 4: Simplify right side
   1,032.72x = 997,229.32
5. Step 5: Solve for x
   x = 997,229.32/1,032.72
6. Step 6: Final answer
   x = 965.63