Finding the Fourth Proportional to 1,411.24, 1,947.45 and 821.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.24 : 1,947.45 = 821.80 : x
2. Step 2: Convert to fraction form
   1,411.24/1,947.45 = 821.80/x
3. Step 3: Cross multiply
   1,411.24x = 1,947.45 × 821.80
4. Step 4: Simplify right side
   1,411.24x = 1,600,414.41
5. Step 5: Solve for x
   x = 1,600,414.41/1,411.24
6. Step 6: Final answer
   x = 1,134.05