Finding the Third Proportional to 290,499 and 396,042

Step by Step Solution

1. Step 1: Write the proportion equation
   290,499 : 396,042 = 396,042 : x
2. Step 2: Convert to fraction form
   290,499/396,042 = 396,042/x
3. Step 3: Cross multiply
   290,499x = 396,042 × 396,042
4. Step 4: Simplify right side
   290,499x = 156,849,265,764
5. Step 5: Solve for x
   x = 156,849,265,764/290,499
6. Step 6: Final answer
   x = 539,930.48