Finding the Fourth Proportional to 1,321.31, 1,823.41 and 817.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.31 : 1,823.41 = 817.39 : x
2. Step 2: Convert to fraction form
   1,321.31/1,823.41 = 817.39/x
3. Step 3: Cross multiply
   1,321.31x = 1,823.41 × 817.39
4. Step 4: Simplify right side
   1,321.31x = 1,490,440.40
5. Step 5: Solve for x
   x = 1,490,440.40/1,321.31
6. Step 6: Final answer
   x = 1,128.00