Finding the Third Proportional to 778,420 and 1,689,716

Step by Step Solution

1. Step 1: Write the proportion equation
   778,420 : 1,689,716 = 1,689,716 : x
2. Step 2: Convert to fraction form
   778,420/1,689,716 = 1,689,716/x
3. Step 3: Cross multiply
   778,420x = 1,689,716 × 1,689,716
4. Step 4: Simplify right side
   778,420x = 2,855,140,160,656
5. Step 5: Solve for x
   x = 2,855,140,160,656/778,420
6. Step 6: Final answer
   x = 3,667,865.88