Finding the Third Proportional to 86,210 and 123,420

Step by Step Solution

1. Step 1: Write the proportion equation
   86,210 : 123,420 = 123,420 : x
2. Step 2: Convert to fraction form
   86,210/123,420 = 123,420/x
3. Step 3: Cross multiply
   86,210x = 123,420 × 123,420
4. Step 4: Simplify right side
   86,210x = 15,232,496,400
5. Step 5: Solve for x
   x = 15,232,496,400/86,210
6. Step 6: Final answer
   x = 176,690.60