Finding the Fourth Proportional to 2,551.74, 3,828.15 and 820.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,551.74 : 3,828.15 = 820.50 : x
2. Step 2: Convert to fraction form
   2,551.74/3,828.15 = 820.50/x
3. Step 3: Cross multiply
   2,551.74x = 3,828.15 × 820.50
4. Step 4: Simplify right side
   2,551.74x = 3,140,997.08
5. Step 5: Solve for x
   x = 3,140,997.08/2,551.74
6. Step 6: Final answer
   x = 1,230.92