Finding the Third Proportional to 13,809 and 20,715

Step by Step Solution

1. Step 1: Write the proportion equation
   13,809 : 20,715 = 20,715 : x
2. Step 2: Convert to fraction form
   13,809/20,715 = 20,715/x
3. Step 3: Cross multiply
   13,809x = 20,715 × 20,715
4. Step 4: Simplify right side
   13,809x = 429,111,225
5. Step 5: Solve for x
   x = 429,111,225/13,809
6. Step 6: Final answer
   x = 31,074.75