Finding the Third Proportional to 2,490 and 5,478

Step by Step Solution

1. Step 1: Write the proportion equation
   2,490 : 5,478 = 5,478 : x
2. Step 2: Convert to fraction form
   2,490/5,478 = 5,478/x
3. Step 3: Cross multiply
   2,490x = 5,478 × 5,478
4. Step 4: Simplify right side
   2,490x = 30,008,484
5. Step 5: Solve for x
   x = 30,008,484/2,490
6. Step 6: Final answer
   x = 12,051.60