Finding the Third Proportional to 11,128.50 and 21,939.75

Step by Step Solution

1. Step 1: Write the proportion equation
   11,128.50 : 21,939.75 = 21,939.75 : x
2. Step 2: Convert to fraction form
   11,128.50/21,939.75 = 21,939.75/x
3. Step 3: Cross multiply
   11,128.50x = 21,939.75 × 21,939.75
4. Step 4: Simplify right side
   11,128.50x = 481,352,630.06
5. Step 5: Solve for x
   x = 481,352,630.06/11,128.50
6. Step 6: Final answer
   x = 43,254.04