Finding the Third Proportional to 5,215,686 and 7,978,500

Step by Step Solution

1. Step 1: Write the proportion equation
   5,215,686 : 7,978,500 = 7,978,500 : x
2. Step 2: Convert to fraction form
   5,215,686/7,978,500 = 7,978,500/x
3. Step 3: Cross multiply
   5,215,686x = 7,978,500 × 7,978,500
4. Step 4: Simplify right side
   5,215,686x = 63,656,462,250,000
5. Step 5: Solve for x
   x = 63,656,462,250,000/5,215,686
6. Step 6: Final answer
   x = 12,204,811.07