Finding the Third Proportional to 11,821.50 and 21,820.50

Step by Step Solution

1. Step 1: Write the proportion equation
   11,821.50 : 21,820.50 = 21,820.50 : x
2. Step 2: Convert to fraction form
   11,821.50/21,820.50 = 21,820.50/x
3. Step 3: Cross multiply
   11,821.50x = 21,820.50 × 21,820.50
4. Step 4: Simplify right side
   11,821.50x = 476,134,220.25
5. Step 5: Solve for x
   x = 476,134,220.25/11,821.50
6. Step 6: Final answer
   x = 40,276.97