Finding the Third Proportional to 2,557 and 5,478.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,557 : 5,478.50 = 5,478.50 : x
2. Step 2: Convert to fraction form
   2,557/5,478.50 = 5,478.50/x
3. Step 3: Cross multiply
   2,557x = 5,478.50 × 5,478.50
4. Step 4: Simplify right side
   2,557x = 30,013,962.25
5. Step 5: Solve for x
   x = 30,013,962.25/2,557
6. Step 6: Final answer
   x = 11,737.96