Finding the Third Proportional to 309.50 and 666.25

Step by Step Solution

1. Step 1: Write the proportion equation
   309.50 : 666.25 = 666.25 : x
2. Step 2: Convert to fraction form
   309.50/666.25 = 666.25/x
3. Step 3: Cross multiply
   309.50x = 666.25 × 666.25
4. Step 4: Simplify right side
   309.50x = 443,889.06
5. Step 5: Solve for x
   x = 443,889.06/309.50
6. Step 6: Final answer
   x = 1,434.21