Finding the Third Proportional to 20,817.75 and 42,406.50

Step by Step Solution

1. Step 1: Write the proportion equation
   20,817.75 : 42,406.50 = 42,406.50 : x
2. Step 2: Convert to fraction form
   20,817.75/42,406.50 = 42,406.50/x
3. Step 3: Cross multiply
   20,817.75x = 42,406.50 × 42,406.50
4. Step 4: Simplify right side
   20,817.75x = 1,798,311,242.25
5. Step 5: Solve for x
   x = 1,798,311,242.25/20,817.75
6. Step 6: Final answer
   x = 86,383.55