Finding the Third Proportional to 111,905 and 218,099

Step by Step Solution

1. Step 1: Write the proportion equation
   111,905 : 218,099 = 218,099 : x
2. Step 2: Convert to fraction form
   111,905/218,099 = 218,099/x
3. Step 3: Cross multiply
   111,905x = 218,099 × 218,099
4. Step 4: Simplify right side
   111,905x = 47,567,173,801
5. Step 5: Solve for x
   x = 47,567,173,801/111,905
6. Step 6: Final answer
   x = 425,067.46