Finding the Third Proportional to 21,431 and 31,309

Step by Step Solution

1. Step 1: Write the proportion equation
   21,431 : 31,309 = 31,309 : x
2. Step 2: Convert to fraction form
   21,431/31,309 = 31,309/x
3. Step 3: Cross multiply
   21,431x = 31,309 × 31,309
4. Step 4: Simplify right side
   21,431x = 980,253,481
5. Step 5: Solve for x
   x = 980,253,481/21,431
6. Step 6: Final answer
   x = 45,739.98