Finding the Fourth Proportional to 2,054.30, 3,080.55 and 821.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,054.30 : 3,080.55 = 821.30 : x
2. Step 2: Convert to fraction form
   2,054.30/3,080.55 = 821.30/x
3. Step 3: Cross multiply
   2,054.30x = 3,080.55 × 821.30
4. Step 4: Simplify right side
   2,054.30x = 2,530,055.72
5. Step 5: Solve for x
   x = 2,530,055.72/2,054.30
6. Step 6: Final answer
   x = 1,231.59