Finding the Third Proportional to 7,868,910 and 12,139,618.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,868,910 : 12,139,618.50 = 12,139,618.50 : x
2. Step 2: Convert to fraction form
   7,868,910/12,139,618.50 = 12,139,618.50/x
3. Step 3: Cross multiply
   7,868,910x = 12,139,618.50 × 12,139,618.50
4. Step 4: Simplify right side
   7,868,910x = 147,370,337,325,542.25
5. Step 5: Solve for x
   x = 147,370,337,325,542.25/7,868,910
6. Step 6: Final answer
   x = 18,728,176.75