Finding the Third Proportional to 8,690 and 13,078

Step by Step Solution

1. Step 1: Write the proportion equation
   8,690 : 13,078 = 13,078 : x
2. Step 2: Convert to fraction form
   8,690/13,078 = 13,078/x
3. Step 3: Cross multiply
   8,690x = 13,078 × 13,078
4. Step 4: Simplify right side
   8,690x = 171,034,084
5. Step 5: Solve for x
   x = 171,034,084/8,690
6. Step 6: Final answer
   x = 19,681.71