Finding the Third Proportional to 5,751.50 and 8,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,751.50 : 8,139.50 = 8,139.50 : x
2. Step 2: Convert to fraction form
   5,751.50/8,139.50 = 8,139.50/x
3. Step 3: Cross multiply
   5,751.50x = 8,139.50 × 8,139.50
4. Step 4: Simplify right side
   5,751.50x = 66,251,460.25
5. Step 5: Solve for x
   x = 66,251,460.25/5,751.50
6. Step 6: Final answer
   x = 11,518.99