Finding the Third Proportional to 21,205 and 31,809

Step by Step Solution

1. Step 1: Write the proportion equation
   21,205 : 31,809 = 31,809 : x
2. Step 2: Convert to fraction form
   21,205/31,809 = 31,809/x
3. Step 3: Cross multiply
   21,205x = 31,809 × 31,809
4. Step 4: Simplify right side
   21,205x = 1,011,812,481
5. Step 5: Solve for x
   x = 1,011,812,481/21,205
6. Step 6: Final answer
   x = 47,715.75