Finding the Third Proportional to 3,912,090 and 8,402,640

Step by Step Solution

1. Step 1: Write the proportion equation
   3,912,090 : 8,402,640 = 8,402,640 : x
2. Step 2: Convert to fraction form
   3,912,090/8,402,640 = 8,402,640/x
3. Step 3: Cross multiply
   3,912,090x = 8,402,640 × 8,402,640
4. Step 4: Simplify right side
   3,912,090x = 70,604,358,969,600
5. Step 5: Solve for x
   x = 70,604,358,969,600/3,912,090
6. Step 6: Final answer
   x = 18,047,733.81