Finding the Fourth Proportional to 2,185.76, 3,278.55 and 869.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.76 : 3,278.55 = 869.45 : x
2. Step 2: Convert to fraction form
   2,185.76/3,278.55 = 869.45/x
3. Step 3: Cross multiply
   2,185.76x = 3,278.55 × 869.45
4. Step 4: Simplify right side
   2,185.76x = 2,850,543.49
5. Step 5: Solve for x
   x = 2,850,543.49/2,185.76
6. Step 6: Final answer
   x = 1,304.15