Finding the Third Proportional to 439,983 and 686,266.50

Step by Step Solution

1. Step 1: Write the proportion equation
   439,983 : 686,266.50 = 686,266.50 : x
2. Step 2: Convert to fraction form
   439,983/686,266.50 = 686,266.50/x
3. Step 3: Cross multiply
   439,983x = 686,266.50 × 686,266.50
4. Step 4: Simplify right side
   439,983x = 470,961,709,022.25
5. Step 5: Solve for x
   x = 470,961,709,022.25/439,983
6. Step 6: Final answer
   x = 1,070,408.88