Finding the Third Proportional to 186,408 and 405,216

Step by Step Solution

1. Step 1: Write the proportion equation
   186,408 : 405,216 = 405,216 : x
2. Step 2: Convert to fraction form
   186,408/405,216 = 405,216/x
3. Step 3: Cross multiply
   186,408x = 405,216 × 405,216
4. Step 4: Simplify right side
   186,408x = 164,200,006,656
5. Step 5: Solve for x
   x = 164,200,006,656/186,408
6. Step 6: Final answer
   x = 880,863.52