Finding the Fourth Proportional to 1,380.76, 1,904.58 and 820.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.76 : 1,904.58 = 820.83 : x
2. Step 2: Convert to fraction form
   1,380.76/1,904.58 = 820.83/x
3. Step 3: Cross multiply
   1,380.76x = 1,904.58 × 820.83
4. Step 4: Simplify right side
   1,380.76x = 1,563,336.40
5. Step 5: Solve for x
   x = 1,563,336.40/1,380.76
6. Step 6: Final answer
   x = 1,132.23