Finding the Third Proportional to 2,790 and 5,509.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,790 : 5,509.50 = 5,509.50 : x
2. Step 2: Convert to fraction form
   2,790/5,509.50 = 5,509.50/x
3. Step 3: Cross multiply
   2,790x = 5,509.50 × 5,509.50
4. Step 4: Simplify right side
   2,790x = 30,354,590.25
5. Step 5: Solve for x
   x = 30,354,590.25/2,790
6. Step 6: Final answer
   x = 10,879.78