Finding the Fourth Proportional to 1,379.76, 1,903.20 and 819.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.76 : 1,903.20 = 819.83 : x
2. Step 2: Convert to fraction form
   1,379.76/1,903.20 = 819.83/x
3. Step 3: Cross multiply
   1,379.76x = 1,903.20 × 819.83
4. Step 4: Simplify right side
   1,379.76x = 1,560,300.46
5. Step 5: Solve for x
   x = 1,560,300.46/1,379.76
6. Step 6: Final answer
   x = 1,130.85