Finding the Third Proportional to 20,139.75 and 42,871.50

Step by Step Solution

1. Step 1: Write the proportion equation
   20,139.75 : 42,871.50 = 42,871.50 : x
2. Step 2: Convert to fraction form
   20,139.75/42,871.50 = 42,871.50/x
3. Step 3: Cross multiply
   20,139.75x = 42,871.50 × 42,871.50
4. Step 4: Simplify right side
   20,139.75x = 1,837,965,512.25
5. Step 5: Solve for x
   x = 1,837,965,512.25/20,139.75
6. Step 6: Final answer
   x = 91,260.59