Finding the Third Proportional to 639,074 and 1,390,900

Step by Step Solution

1. Step 1: Write the proportion equation
   639,074 : 1,390,900 = 1,390,900 : x
2. Step 2: Convert to fraction form
   639,074/1,390,900 = 1,390,900/x
3. Step 3: Cross multiply
   639,074x = 1,390,900 × 1,390,900
4. Step 4: Simplify right side
   639,074x = 1,934,602,810,000
5. Step 5: Solve for x
   x = 1,934,602,810,000/639,074
6. Step 6: Final answer
   x = 3,027,196.87