Finding the Third Proportional to 11,720 and 20,521

Step by Step Solution

1. Step 1: Write the proportion equation
   11,720 : 20,521 = 20,521 : x
2. Step 2: Convert to fraction form
   11,720/20,521 = 20,521/x
3. Step 3: Cross multiply
   11,720x = 20,521 × 20,521
4. Step 4: Simplify right side
   11,720x = 421,111,441
5. Step 5: Solve for x
   x = 421,111,441/11,720
6. Step 6: Final answer
   x = 35,931.01