Finding the Third Proportional to 10,422 and 21,270

Step by Step Solution

1. Step 1: Write the proportion equation
   10,422 : 21,270 = 21,270 : x
2. Step 2: Convert to fraction form
   10,422/21,270 = 21,270/x
3. Step 3: Cross multiply
   10,422x = 21,270 × 21,270
4. Step 4: Simplify right side
   10,422x = 452,412,900
5. Step 5: Solve for x
   x = 452,412,900/10,422
6. Step 6: Final answer
   x = 43,409.41