Finding the Third Proportional to 117.28 and 280.69

Step by Step Solution

1. Step 1: Write the proportion equation
   117.28 : 280.69 = 280.69 : x
2. Step 2: Convert to fraction form
   117.28/280.69 = 280.69/x
3. Step 3: Cross multiply
   117.28x = 280.69 × 280.69
4. Step 4: Simplify right side
   117.28x = 78,785.47
5. Step 5: Solve for x
   x = 78,785.47/117.28
6. Step 6: Final answer
   x = 671.77