Finding the Third Proportional to 99,778 and 213,392

Step by Step Solution

1. Step 1: Write the proportion equation
   99,778 : 213,392 = 213,392 : x
2. Step 2: Convert to fraction form
   99,778/213,392 = 213,392/x
3. Step 3: Cross multiply
   99,778x = 213,392 × 213,392
4. Step 4: Simplify right side
   99,778x = 45,536,145,664
5. Step 5: Solve for x
   x = 45,536,145,664/99,778
6. Step 6: Final answer
   x = 456,374.61