Finding the Third Proportional to 5,215 and 10,861.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,215 : 10,861.50 = 10,861.50 : x
2. Step 2: Convert to fraction form
   5,215/10,861.50 = 10,861.50/x
3. Step 3: Cross multiply
   5,215x = 10,861.50 × 10,861.50
4. Step 4: Simplify right side
   5,215x = 117,972,182.25
5. Step 5: Solve for x
   x = 117,972,182.25/5,215
6. Step 6: Final answer
   x = 22,621.70