Finding the Third Proportional to 639,072 and 1,390,896

Step by Step Solution

1. Step 1: Write the proportion equation
   639,072 : 1,390,896 = 1,390,896 : x
2. Step 2: Convert to fraction form
   639,072/1,390,896 = 1,390,896/x
3. Step 3: Cross multiply
   639,072x = 1,390,896 × 1,390,896
4. Step 4: Simplify right side
   639,072x = 1,934,591,682,816
5. Step 5: Solve for x
   x = 1,934,591,682,816/639,072
6. Step 6: Final answer
   x = 3,027,188.93