Finding the Third Proportional to 9,915 and 13,158

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915 : 13,158 = 13,158 : x
2. Step 2: Convert to fraction form
   9,915/13,158 = 13,158/x
3. Step 3: Cross multiply
   9,915x = 13,158 × 13,158
4. Step 4: Simplify right side
   9,915x = 173,132,964
5. Step 5: Solve for x
   x = 173,132,964/9,915
6. Step 6: Final answer
   x = 17,461.72