Finding the Third Proportional to 20,856 and 43,172

Step by Step Solution

1. Step 1: Write the proportion equation
   20,856 : 43,172 = 43,172 : x
2. Step 2: Convert to fraction form
   20,856/43,172 = 43,172/x
3. Step 3: Cross multiply
   20,856x = 43,172 × 43,172
4. Step 4: Simplify right side
   20,856x = 1,863,821,584
5. Step 5: Solve for x
   x = 1,863,821,584/20,856
6. Step 6: Final answer
   x = 89,366.21