Finding the Fourth Proportional to 1,553.10, 2,326.59 and 820.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,553.10 : 2,326.59 = 820.86 : x
2. Step 2: Convert to fraction form
   1,553.10/2,326.59 = 820.86/x
3. Step 3: Cross multiply
   1,553.10x = 2,326.59 × 820.86
4. Step 4: Simplify right side
   1,553.10x = 1,909,804.67
5. Step 5: Solve for x
   x = 1,909,804.67/1,553.10
6. Step 6: Final answer
   x = 1,229.67