Finding the Third Proportional to 317,838 and 686,089.50

Step by Step Solution

1. Step 1: Write the proportion equation
   317,838 : 686,089.50 = 686,089.50 : x
2. Step 2: Convert to fraction form
   317,838/686,089.50 = 686,089.50/x
3. Step 3: Cross multiply
   317,838x = 686,089.50 × 686,089.50
4. Step 4: Simplify right side
   317,838x = 470,718,802,010.25
5. Step 5: Solve for x
   x = 470,718,802,010.25/317,838
6. Step 6: Final answer
   x = 1,481,002.28