Finding the Third Proportional to 309.94 and 667.69

Step by Step Solution

1. Step 1: Write the proportion equation
   309.94 : 667.69 = 667.69 : x
2. Step 2: Convert to fraction form
   309.94/667.69 = 667.69/x
3. Step 3: Cross multiply
   309.94x = 667.69 × 667.69
4. Step 4: Simplify right side
   309.94x = 445,806.60
5. Step 5: Solve for x
   x = 445,806.60/309.94
6. Step 6: Final answer
   x = 1,438.38