Finding the Third Proportional to 10,221.75 and 20,686.50

Step by Step Solution

1. Step 1: Write the proportion equation
   10,221.75 : 20,686.50 = 20,686.50 : x
2. Step 2: Convert to fraction form
   10,221.75/20,686.50 = 20,686.50/x
3. Step 3: Cross multiply
   10,221.75x = 20,686.50 × 20,686.50
4. Step 4: Simplify right side
   10,221.75x = 427,931,282.25
5. Step 5: Solve for x
   x = 427,931,282.25/10,221.75
6. Step 6: Final answer
   x = 41,864.78