Finding the Third Proportional to 142,920 and 210,009

Step by Step Solution

1. Step 1: Write the proportion equation
   142,920 : 210,009 = 210,009 : x
2. Step 2: Convert to fraction form
   142,920/210,009 = 210,009/x
3. Step 3: Cross multiply
   142,920x = 210,009 × 210,009
4. Step 4: Simplify right side
   142,920x = 44,103,780,081
5. Step 5: Solve for x
   x = 44,103,780,081/142,920
6. Step 6: Final answer
   x = 308,590.68