Finding the Third Proportional to 128.14 and 280.32

Step by Step Solution

1. Step 1: Write the proportion equation
   128.14 : 280.32 = 280.32 : x
2. Step 2: Convert to fraction form
   128.14/280.32 = 280.32/x
3. Step 3: Cross multiply
   128.14x = 280.32 × 280.32
4. Step 4: Simplify right side
   128.14x = 78,577.15
5. Step 5: Solve for x
   x = 78,577.15/128.14
6. Step 6: Final answer
   x = 613.19