Finding the Third Proportional to 10,915.50 and 16,686.50

Step by Step Solution

1. Step 1: Write the proportion equation
   10,915.50 : 16,686.50 = 16,686.50 : x
2. Step 2: Convert to fraction form
   10,915.50/16,686.50 = 16,686.50/x
3. Step 3: Cross multiply
   10,915.50x = 16,686.50 × 16,686.50
4. Step 4: Simplify right side
   10,915.50x = 278,439,282.25
5. Step 5: Solve for x
   x = 278,439,282.25/10,915.50
6. Step 6: Final answer
   x = 25,508.61