Finding the Third Proportional to 86,580 and 129,870

Step by Step Solution

1. Step 1: Write the proportion equation
   86,580 : 129,870 = 129,870 : x
2. Step 2: Convert to fraction form
   86,580/129,870 = 129,870/x
3. Step 3: Cross multiply
   86,580x = 129,870 × 129,870
4. Step 4: Simplify right side
   86,580x = 16,866,216,900
5. Step 5: Solve for x
   x = 16,866,216,900/86,580
6. Step 6: Final answer
   x = 194,805