Finding the Third Proportional to 199,638 and 309,628.50

Step by Step Solution

1. Step 1: Write the proportion equation
   199,638 : 309,628.50 = 309,628.50 : x
2. Step 2: Convert to fraction form
   199,638/309,628.50 = 309,628.50/x
3. Step 3: Cross multiply
   199,638x = 309,628.50 × 309,628.50
4. Step 4: Simplify right side
   199,638x = 95,869,808,012.25
5. Step 5: Solve for x
   x = 95,869,808,012.25/199,638
6. Step 6: Final answer
   x = 480,218.24