Finding the Third Proportional to 11,091 and 15,405

Step by Step Solution

1. Step 1: Write the proportion equation
   11,091 : 15,405 = 15,405 : x
2. Step 2: Convert to fraction form
   11,091/15,405 = 15,405/x
3. Step 3: Cross multiply
   11,091x = 15,405 × 15,405
4. Step 4: Simplify right side
   11,091x = 237,314,025
5. Step 5: Solve for x
   x = 237,314,025/11,091
6. Step 6: Final answer
   x = 21,396.99