Finding the Fourth Proportional to 1,215,513.97, 1,677,408.72 and 671,645

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215,513.97 : 1,677,408.72 = 671,645 : x
2. Step 2: Convert to fraction form
   1,215,513.97/1,677,408.72 = 671,645/x
3. Step 3: Cross multiply
   1,215,513.97x = 1,677,408.72 × 671,645
4. Step 4: Simplify right side
   1,215,513.97x = 1,126,623,179,744.40
5. Step 5: Solve for x
   x = 1,126,623,179,744.40/1,215,513.97
6. Step 6: Final answer
   x = 926,869.79