Finding the Fourth Proportional to 1,442.56, 1,990.64 and 821.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.56 : 1,990.64 = 821.52 : x
2. Step 2: Convert to fraction form
   1,442.56/1,990.64 = 821.52/x
3. Step 3: Cross multiply
   1,442.56x = 1,990.64 × 821.52
4. Step 4: Simplify right side
   1,442.56x = 1,635,350.57
5. Step 5: Solve for x
   x = 1,635,350.57/1,442.56
6. Step 6: Final answer
   x = 1,133.64