Finding the Third Proportional to 42,409 and 72,220

Step by Step Solution

1. Step 1: Write the proportion equation
   42,409 : 72,220 = 72,220 : x
2. Step 2: Convert to fraction form
   42,409/72,220 = 72,220/x
3. Step 3: Cross multiply
   42,409x = 72,220 × 72,220
4. Step 4: Simplify right side
   42,409x = 5,215,728,400
5. Step 5: Solve for x
   x = 5,215,728,400/42,409
6. Step 6: Final answer
   x = 122,986.36