Finding the Third Proportional to 487.69 and 728.72

Step by Step Solution

1. Step 1: Write the proportion equation
   487.69 : 728.72 = 728.72 : x
2. Step 2: Convert to fraction form
   487.69/728.72 = 728.72/x
3. Step 3: Cross multiply
   487.69x = 728.72 × 728.72
4. Step 4: Simplify right side
   487.69x = 531,031.02
5. Step 5: Solve for x
   x = 531,031.02/487.69
6. Step 6: Final answer
   x = 1,088.88