Finding the Third Proportional to 9,915 and 21,558

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915 : 21,558 = 21,558 : x
2. Step 2: Convert to fraction form
   9,915/21,558 = 21,558/x
3. Step 3: Cross multiply
   9,915x = 21,558 × 21,558
4. Step 4: Simplify right side
   9,915x = 464,747,364
5. Step 5: Solve for x
   x = 464,747,364/9,915
6. Step 6: Final answer
   x = 46,873.16