Finding the Third Proportional to 7,860 and 12,631.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,860 : 12,631.50 = 12,631.50 : x
2. Step 2: Convert to fraction form
   7,860/12,631.50 = 12,631.50/x
3. Step 3: Cross multiply
   7,860x = 12,631.50 × 12,631.50
4. Step 4: Simplify right side
   7,860x = 159,554,792.25
5. Step 5: Solve for x
   x = 159,554,792.25/7,860
6. Step 6: Final answer
   x = 20,299.59