Finding the Fourth Proportional to 1,277.72, 1,916.16 and 411.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,277.72 : 1,916.16 = 411.82 : x
2. Step 2: Convert to fraction form
   1,277.72/1,916.16 = 411.82/x
3. Step 3: Cross multiply
   1,277.72x = 1,916.16 × 411.82
4. Step 4: Simplify right side
   1,277.72x = 789,113.01
5. Step 5: Solve for x
   x = 789,113.01/1,277.72
6. Step 6: Final answer
   x = 617.59