Finding the Fourth Proportional to 2,185.76, 3,278.71 and 542.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.76 : 3,278.71 = 542.31 : x
2. Step 2: Convert to fraction form
   2,185.76/3,278.71 = 542.31/x
3. Step 3: Cross multiply
   2,185.76x = 3,278.71 × 542.31
4. Step 4: Simplify right side
   2,185.76x = 1,778,077.22
5. Step 5: Solve for x
   x = 1,778,077.22/2,185.76
6. Step 6: Final answer
   x = 813.48