Finding the Fourth Proportional to 2,553.28, 3,830.46 and 821.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,553.28 : 3,830.46 = 821.50 : x
2. Step 2: Convert to fraction form
   2,553.28/3,830.46 = 821.50/x
3. Step 3: Cross multiply
   2,553.28x = 3,830.46 × 821.50
4. Step 4: Simplify right side
   2,553.28x = 3,146,722.89
5. Step 5: Solve for x
   x = 3,146,722.89/2,553.28
6. Step 6: Final answer
   x = 1,232.42