Finding the Third Proportional to 2,478.09 and 5,161.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,478.09 : 5,161.78 = 5,161.78 : x
2. Step 2: Convert to fraction form
   2,478.09/5,161.78 = 5,161.78/x
3. Step 3: Cross multiply
   2,478.09x = 5,161.78 × 5,161.78
4. Step 4: Simplify right side
   2,478.09x = 26,643,985.67
5. Step 5: Solve for x
   x = 26,643,985.67/2,478.09
6. Step 6: Final answer
   x = 10,751.81