Finding the Fourth Proportional to 2,679.35, 4,016.72 and 1,290.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,679.35 : 4,016.72 = 1,290.78 : x
2. Step 2: Convert to fraction form
   2,679.35/4,016.72 = 1,290.78/x
3. Step 3: Cross multiply
   2,679.35x = 4,016.72 × 1,290.78
4. Step 4: Simplify right side
   2,679.35x = 5,184,701.84
5. Step 5: Solve for x
   x = 5,184,701.84/2,679.35
6. Step 6: Final answer
   x = 1,935.06