Finding the Third Proportional to 1,167,992 and 1,290,872

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167,992 : 1,290,872 = 1,290,872 : x
2. Step 2: Convert to fraction form
   1,167,992/1,290,872 = 1,290,872/x
3. Step 3: Cross multiply
   1,167,992x = 1,290,872 × 1,290,872
4. Step 4: Simplify right side
   1,167,992x = 1,666,350,520,384
5. Step 5: Solve for x
   x = 1,666,350,520,384/1,167,992
6. Step 6: Final answer
   x = 1,426,679.74