Finding the Third Proportional to 216,580 and 324,870

Step by Step Solution

1. Step 1: Write the proportion equation
   216,580 : 324,870 = 324,870 : x
2. Step 2: Convert to fraction form
   216,580/324,870 = 324,870/x
3. Step 3: Cross multiply
   216,580x = 324,870 × 324,870
4. Step 4: Simplify right side
   216,580x = 105,540,516,900
5. Step 5: Solve for x
   x = 105,540,516,900/216,580
6. Step 6: Final answer
   x = 487,305