Finding the Third Proportional to 9,920,570 and 21,258,316

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920,570 : 21,258,316 = 21,258,316 : x
2. Step 2: Convert to fraction form
   9,920,570/21,258,316 = 21,258,316/x
3. Step 3: Cross multiply
   9,920,570x = 21,258,316 × 21,258,316
4. Step 4: Simplify right side
   9,920,570x = 451,915,999,155,856
5. Step 5: Solve for x
   x = 451,915,999,155,856/9,920,570
6. Step 6: Final answer
   x = 45,553,430.82