Finding the Third Proportional to 3,867,434 and 8,428,138

Step by Step Solution

1. Step 1: Write the proportion equation
   3,867,434 : 8,428,138 = 8,428,138 : x
2. Step 2: Convert to fraction form
   3,867,434/8,428,138 = 8,428,138/x
3. Step 3: Cross multiply
   3,867,434x = 8,428,138 × 8,428,138
4. Step 4: Simplify right side
   3,867,434x = 71,033,510,147,044
5. Step 5: Solve for x
   x = 71,033,510,147,044/3,867,434
6. Step 6: Final answer
   x = 18,367,090.47