Finding the Third Proportional to 271,867 and 390,061

Step by Step Solution

1. Step 1: Write the proportion equation
   271,867 : 390,061 = 390,061 : x
2. Step 2: Convert to fraction form
   271,867/390,061 = 390,061/x
3. Step 3: Cross multiply
   271,867x = 390,061 × 390,061
4. Step 4: Simplify right side
   271,867x = 152,147,583,721
5. Step 5: Solve for x
   x = 152,147,583,721/271,867
6. Step 6: Final answer
   x = 559,639.76