Finding the Third Proportional to 639,790 and 1,368,140

Step by Step Solution

1. Step 1: Write the proportion equation
   639,790 : 1,368,140 = 1,368,140 : x
2. Step 2: Convert to fraction form
   639,790/1,368,140 = 1,368,140/x
3. Step 3: Cross multiply
   639,790x = 1,368,140 × 1,368,140
4. Step 4: Simplify right side
   639,790x = 1,871,807,059,600
5. Step 5: Solve for x
   x = 1,871,807,059,600/639,790
6. Step 6: Final answer
   x = 2,925,658.51