Finding the Third Proportional to 99,678 and 218,040

Step by Step Solution

1. Step 1: Write the proportion equation
   99,678 : 218,040 = 218,040 : x
2. Step 2: Convert to fraction form
   99,678/218,040 = 218,040/x
3. Step 3: Cross multiply
   99,678x = 218,040 × 218,040
4. Step 4: Simplify right side
   99,678x = 47,541,441,600
5. Step 5: Solve for x
   x = 47,541,441,600/99,678
6. Step 6: Final answer
   x = 476,950.20