Finding the Third Proportional to 1,921,390 and 4,139,685

Step by Step Solution

1. Step 1: Write the proportion equation
   1,921,390 : 4,139,685 = 4,139,685 : x
2. Step 2: Convert to fraction form
   1,921,390/4,139,685 = 4,139,685/x
3. Step 3: Cross multiply
   1,921,390x = 4,139,685 × 4,139,685
4. Step 4: Simplify right side
   1,921,390x = 17,136,991,899,225
5. Step 5: Solve for x
   x = 17,136,991,899,225/1,921,390
6. Step 6: Final answer
   x = 8,919,059.59