Finding the Third Proportional to 261,231 and 390,834

Step by Step Solution

1. Step 1: Write the proportion equation
   261,231 : 390,834 = 390,834 : x
2. Step 2: Convert to fraction form
   261,231/390,834 = 390,834/x
3. Step 3: Cross multiply
   261,231x = 390,834 × 390,834
4. Step 4: Simplify right side
   261,231x = 152,751,215,556
5. Step 5: Solve for x
   x = 152,751,215,556/261,231
6. Step 6: Final answer
   x = 584,736.17