Finding the Third Proportional to 387,390 and 839,122.50

Step by Step Solution

1. Step 1: Write the proportion equation
   387,390 : 839,122.50 = 839,122.50 : x
2. Step 2: Convert to fraction form
   387,390/839,122.50 = 839,122.50/x
3. Step 3: Cross multiply
   387,390x = 839,122.50 × 839,122.50
4. Step 4: Simplify right side
   387,390x = 704,126,570,006.25
5. Step 5: Solve for x
   x = 704,126,570,006.25/387,390
6. Step 6: Final answer
   x = 1,817,616.79