Finding the Third Proportional to 42,406 and 72,215

Step by Step Solution

1. Step 1: Write the proportion equation
   42,406 : 72,215 = 72,215 : x
2. Step 2: Convert to fraction form
   42,406/72,215 = 72,215/x
3. Step 3: Cross multiply
   42,406x = 72,215 × 72,215
4. Step 4: Simplify right side
   42,406x = 5,215,006,225
5. Step 5: Solve for x
   x = 5,215,006,225/42,406
6. Step 6: Final answer
   x = 122,978.03