Finding the Third Proportional to 12,639 and 27,870

Step by Step Solution

1. Step 1: Write the proportion equation
   12,639 : 27,870 = 27,870 : x
2. Step 2: Convert to fraction form
   12,639/27,870 = 27,870/x
3. Step 3: Cross multiply
   12,639x = 27,870 × 27,870
4. Step 4: Simplify right side
   12,639x = 776,736,900
5. Step 5: Solve for x
   x = 776,736,900/12,639
6. Step 6: Final answer
   x = 61,455.57