Finding the Third Proportional to 643,968 and 1,398,690

Step by Step Solution

1. Step 1: Write the proportion equation
   643,968 : 1,398,690 = 1,398,690 : x
2. Step 2: Convert to fraction form
   643,968/1,398,690 = 1,398,690/x
3. Step 3: Cross multiply
   643,968x = 1,398,690 × 1,398,690
4. Step 4: Simplify right side
   643,968x = 1,956,333,716,100
5. Step 5: Solve for x
   x = 1,956,333,716,100/643,968
6. Step 6: Final answer
   x = 3,037,936.23