Finding the Fourth Proportional to 1,411.16, 1,947.22 and 821.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.16 : 1,947.22 = 821.78 : x
2. Step 2: Convert to fraction form
   1,411.16/1,947.22 = 821.78/x
3. Step 3: Cross multiply
   1,411.16x = 1,947.22 × 821.78
4. Step 4: Simplify right side
   1,411.16x = 1,600,186.45
5. Step 5: Solve for x
   x = 1,600,186.45/1,411.16
6. Step 6: Final answer
   x = 1,133.95