Finding the Third Proportional to 2,171.81 and 5,179.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.81 : 5,179.78 = 5,179.78 : x
2. Step 2: Convert to fraction form
   2,171.81/5,179.78 = 5,179.78/x
3. Step 3: Cross multiply
   2,171.81x = 5,179.78 × 5,179.78
4. Step 4: Simplify right side
   2,171.81x = 26,830,133.80
5. Step 5: Solve for x
   x = 26,830,133.80/2,171.81
6. Step 6: Final answer
   x = 12,353.80