Finding the Fourth Proportional to 2,665.34, 3,998.19 and 1,278.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.34 : 3,998.19 = 1,278.98 : x
2. Step 2: Convert to fraction form
   2,665.34/3,998.19 = 1,278.98/x
3. Step 3: Cross multiply
   2,665.34x = 3,998.19 × 1,278.98
4. Step 4: Simplify right side
   2,665.34x = 5,113,605.05
5. Step 5: Solve for x
   x = 5,113,605.05/2,665.34
6. Step 6: Final answer
   x = 1,918.56