Finding the Fourth Proportional to 2,185.88, 3,278.72 and 542.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.88 : 3,278.72 = 542.38 : x
2. Step 2: Convert to fraction form
   2,185.88/3,278.72 = 542.38/x
3. Step 3: Cross multiply
   2,185.88x = 3,278.72 × 542.38
4. Step 4: Simplify right side
   2,185.88x = 1,778,312.15
5. Step 5: Solve for x
   x = 1,778,312.15/2,185.88
6. Step 6: Final answer
   x = 813.55