Finding the Third Proportional to 91,778 and 139,413

Step by Step Solution

1. Step 1: Write the proportion equation
   91,778 : 139,413 = 139,413 : x
2. Step 2: Convert to fraction form
   91,778/139,413 = 139,413/x
3. Step 3: Cross multiply
   91,778x = 139,413 × 139,413
4. Step 4: Simplify right side
   91,778x = 19,435,984,569
5. Step 5: Solve for x
   x = 19,435,984,569/91,778
6. Step 6: Final answer
   x = 211,771.72