Finding the Third Proportional to 3,900 and 5,486

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900 : 5,486 = 5,486 : x
2. Step 2: Convert to fraction form
   3,900/5,486 = 5,486/x
3. Step 3: Cross multiply
   3,900x = 5,486 × 5,486
4. Step 4: Simplify right side
   3,900x = 30,096,196
5. Step 5: Solve for x
   x = 30,096,196/3,900
6. Step 6: Final answer
   x = 7,716.97