Finding the Fourth Proportional to 2,667.80, 3,998.97 and 1,280.14

Step by Step Solution

1. Step 1: Write the proportion equation
   2,667.80 : 3,998.97 = 1,280.14 : x
2. Step 2: Convert to fraction form
   2,667.80/3,998.97 = 1,280.14/x
3. Step 3: Cross multiply
   2,667.80x = 3,998.97 × 1,280.14
4. Step 4: Simplify right side
   2,667.80x = 5,119,231.46
5. Step 5: Solve for x
   x = 5,119,231.46/2,667.80
6. Step 6: Final answer
   x = 1,918.89