Finding the Third Proportional to 5,257.88 and 8,139.94

Step by Step Solution

1. Step 1: Write the proportion equation
   5,257.88 : 8,139.94 = 8,139.94 : x
2. Step 2: Convert to fraction form
   5,257.88/8,139.94 = 8,139.94/x
3. Step 3: Cross multiply
   5,257.88x = 8,139.94 × 8,139.94
4. Step 4: Simplify right side
   5,257.88x = 66,258,582.50
5. Step 5: Solve for x
   x = 66,258,582.50/5,257.88
6. Step 6: Final answer
   x = 12,601.78