Finding the Third Proportional to 3,300 and 3,900

Step by Step Solution

1. Step 1: Write the proportion equation
   3,300 : 3,900 = 3,900 : x
2. Step 2: Convert to fraction form
   3,300/3,900 = 3,900/x
3. Step 3: Cross multiply
   3,300x = 3,900 × 3,900
4. Step 4: Simplify right side
   3,300x = 15,210,000
5. Step 5: Solve for x
   x = 15,210,000/3,300
6. Step 6: Final answer
   x = 4,609.09