Finding the Third Proportional to 142,905 and 308,409

Step by Step Solution

1. Step 1: Write the proportion equation
   142,905 : 308,409 = 308,409 : x
2. Step 2: Convert to fraction form
   142,905/308,409 = 308,409/x
3. Step 3: Cross multiply
   142,905x = 308,409 × 308,409
4. Step 4: Simplify right side
   142,905x = 95,116,111,281
5. Step 5: Solve for x
   x = 95,116,111,281/142,905
6. Step 6: Final answer
   x = 665,589.81