Finding the Third Proportional to 7,831.50 and 12,140.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,831.50 : 12,140.50 = 12,140.50 : x
2. Step 2: Convert to fraction form
   7,831.50/12,140.50 = 12,140.50/x
3. Step 3: Cross multiply
   7,831.50x = 12,140.50 × 12,140.50
4. Step 4: Simplify right side
   7,831.50x = 147,391,740.25
5. Step 5: Solve for x
   x = 147,391,740.25/7,831.50
6. Step 6: Final answer
   x = 18,820.37