Finding the Third Proportional to 308.88 and 490.69

Step by Step Solution

1. Step 1: Write the proportion equation
   308.88 : 490.69 = 490.69 : x
2. Step 2: Convert to fraction form
   308.88/490.69 = 490.69/x
3. Step 3: Cross multiply
   308.88x = 490.69 × 490.69
4. Step 4: Simplify right side
   308.88x = 240,774.22
5. Step 5: Solve for x
   x = 240,774.22/308.88
6. Step 6: Final answer
   x = 779.52