Finding the Third Proportional to 99,839 and 217,173

Step by Step Solution

1. Step 1: Write the proportion equation
   99,839 : 217,173 = 217,173 : x
2. Step 2: Convert to fraction form
   99,839/217,173 = 217,173/x
3. Step 3: Cross multiply
   99,839x = 217,173 × 217,173
4. Step 4: Simplify right side
   99,839x = 47,164,111,929
5. Step 5: Solve for x
   x = 47,164,111,929/99,839
6. Step 6: Final answer
   x = 472,401.69