Finding the Third Proportional to 307,926 and 661,688

Step by Step Solution

1. Step 1: Write the proportion equation
   307,926 : 661,688 = 661,688 : x
2. Step 2: Convert to fraction form
   307,926/661,688 = 661,688/x
3. Step 3: Cross multiply
   307,926x = 661,688 × 661,688
4. Step 4: Simplify right side
   307,926x = 437,831,009,344
5. Step 5: Solve for x
   x = 437,831,009,344/307,926
6. Step 6: Final answer
   x = 1,421,870.87