Finding the Fourth Proportional to 2,005.78, 3,008.82 and 545.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,005.78 : 3,008.82 = 545.05 : x
2. Step 2: Convert to fraction form
   2,005.78/3,008.82 = 545.05/x
3. Step 3: Cross multiply
   2,005.78x = 3,008.82 × 545.05
4. Step 4: Simplify right side
   2,005.78x = 1,639,957.34
5. Step 5: Solve for x
   x = 1,639,957.34/2,005.78
6. Step 6: Final answer
   x = 817.62