Finding the Third Proportional to 261,336 and 390,981

Step by Step Solution

1. Step 1: Write the proportion equation
   261,336 : 390,981 = 390,981 : x
2. Step 2: Convert to fraction form
   261,336/390,981 = 390,981/x
3. Step 3: Cross multiply
   261,336x = 390,981 × 390,981
4. Step 4: Simplify right side
   261,336x = 152,866,142,361
5. Step 5: Solve for x
   x = 152,866,142,361/261,336
6. Step 6: Final answer
   x = 584,941.00