Finding the Third Proportional to 20,911.50 and 42,687

Step by Step Solution

1. Step 1: Write the proportion equation
   20,911.50 : 42,687 = 42,687 : x
2. Step 2: Convert to fraction form
   20,911.50/42,687 = 42,687/x
3. Step 3: Cross multiply
   20,911.50x = 42,687 × 42,687
4. Step 4: Simplify right side
   20,911.50x = 1,822,179,969
5. Step 5: Solve for x
   x = 1,822,179,969/20,911.50
6. Step 6: Final answer
   x = 87,137.70