Finding the Fourth Proportional to 1,379.50, 1,904.03 and 820.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.50 : 1,904.03 = 820.28 : x
2. Step 2: Convert to fraction form
   1,379.50/1,904.03 = 820.28/x
3. Step 3: Cross multiply
   1,379.50x = 1,904.03 × 820.28
4. Step 4: Simplify right side
   1,379.50x = 1,561,837.73
5. Step 5: Solve for x
   x = 1,561,837.73/1,379.50
6. Step 6: Final answer
   x = 1,132.18