Finding the Third Proportional to 408,072 and 612,111

Step by Step Solution

1. Step 1: Write the proportion equation
   408,072 : 612,111 = 612,111 : x
2. Step 2: Convert to fraction form
   408,072/612,111 = 612,111/x
3. Step 3: Cross multiply
   408,072x = 612,111 × 612,111
4. Step 4: Simplify right side
   408,072x = 374,679,876,321
5. Step 5: Solve for x
   x = 374,679,876,321/408,072
6. Step 6: Final answer
   x = 918,171.00