Finding the Third Proportional to 12,856.50 and 27,990

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856.50 : 27,990 = 27,990 : x
2. Step 2: Convert to fraction form
   12,856.50/27,990 = 27,990/x
3. Step 3: Cross multiply
   12,856.50x = 27,990 × 27,990
4. Step 4: Simplify right side
   12,856.50x = 783,440,100
5. Step 5: Solve for x
   x = 783,440,100/12,856.50
6. Step 6: Final answer
   x = 60,937.28