Finding the Third Proportional to 3,578.34 and 7,686.56

Step by Step Solution

1. Step 1: Write the proportion equation
   3,578.34 : 7,686.56 = 7,686.56 : x
2. Step 2: Convert to fraction form
   3,578.34/7,686.56 = 7,686.56/x
3. Step 3: Cross multiply
   3,578.34x = 7,686.56 × 7,686.56
4. Step 4: Simplify right side
   3,578.34x = 59,083,243.07
5. Step 5: Solve for x
   x = 59,083,243.07/3,578.34
6. Step 6: Final answer
   x = 16,511.34