Finding the Fourth Proportional to 2,185.89, 3,278.82 and 542.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.89 : 3,278.82 = 542.42 : x
2. Step 2: Convert to fraction form
   2,185.89/3,278.82 = 542.42/x
3. Step 3: Cross multiply
   2,185.89x = 3,278.82 × 542.42
4. Step 4: Simplify right side
   2,185.89x = 1,778,502.60
5. Step 5: Solve for x
   x = 1,778,502.60/2,185.89
6. Step 6: Final answer
   x = 813.63