Finding the Third Proportional to 11,815.88 and 15,766.31

Step by Step Solution

1. Step 1: Write the proportion equation
   11,815.88 : 15,766.31 = 15,766.31 : x
2. Step 2: Convert to fraction form
   11,815.88/15,766.31 = 15,766.31/x
3. Step 3: Cross multiply
   11,815.88x = 15,766.31 × 15,766.31
4. Step 4: Simplify right side
   11,815.88x = 248,576,609.85
5. Step 5: Solve for x
   x = 248,576,609.85/11,815.88
6. Step 6: Final answer
   x = 21,037.51