Finding the Third Proportional to 9,902 and 21,420

Step by Step Solution

1. Step 1: Write the proportion equation
   9,902 : 21,420 = 21,420 : x
2. Step 2: Convert to fraction form
   9,902/21,420 = 21,420/x
3. Step 3: Cross multiply
   9,902x = 21,420 × 21,420
4. Step 4: Simplify right side
   9,902x = 458,816,400
5. Step 5: Solve for x
   x = 458,816,400/9,902
6. Step 6: Final answer
   x = 46,335.73