Finding the Fourth Proportional to 2,185.59, 3,278.39 and 542.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.59 : 3,278.39 = 542.10 : x
2. Step 2: Convert to fraction form
   2,185.59/3,278.39 = 542.10/x
3. Step 3: Cross multiply
   2,185.59x = 3,278.39 × 542.10
4. Step 4: Simplify right side
   2,185.59x = 1,777,212.51
5. Step 5: Solve for x
   x = 1,777,212.51/2,185.59
6. Step 6: Final answer
   x = 813.15