Finding the Third Proportional to 39,870 and 54,172

Step by Step Solution

1. Step 1: Write the proportion equation
   39,870 : 54,172 = 54,172 : x
2. Step 2: Convert to fraction form
   39,870/54,172 = 54,172/x
3. Step 3: Cross multiply
   39,870x = 54,172 × 54,172
4. Step 4: Simplify right side
   39,870x = 2,934,605,584
5. Step 5: Solve for x
   x = 2,934,605,584/39,870
6. Step 6: Final answer
   x = 73,604.35