Finding the Third Proportional to 1,390,428 and 2,151,798

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390,428 : 2,151,798 = 2,151,798 : x
2. Step 2: Convert to fraction form
   1,390,428/2,151,798 = 2,151,798/x
3. Step 3: Cross multiply
   1,390,428x = 2,151,798 × 2,151,798
4. Step 4: Simplify right side
   1,390,428x = 4,630,234,632,804
5. Step 5: Solve for x
   x = 4,630,234,632,804/1,390,428
6. Step 6: Final answer
   x = 3,330,078.68