Finding the Third Proportional to 8,640 and 13,113

Step by Step Solution

1. Step 1: Write the proportion equation
   8,640 : 13,113 = 13,113 : x
2. Step 2: Convert to fraction form
   8,640/13,113 = 13,113/x
3. Step 3: Cross multiply
   8,640x = 13,113 × 13,113
4. Step 4: Simplify right side
   8,640x = 171,950,769
5. Step 5: Solve for x
   x = 171,950,769/8,640
6. Step 6: Final answer
   x = 19,901.71