Finding the Fourth Proportional to 1,418.80, 2,117.92 and 1,311.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,418.80 : 2,117.92 = 1,311.88 : x
2. Step 2: Convert to fraction form
   1,418.80/2,117.92 = 1,311.88/x
3. Step 3: Cross multiply
   1,418.80x = 2,117.92 × 1,311.88
4. Step 4: Simplify right side
   1,418.80x = 2,778,456.89
5. Step 5: Solve for x
   x = 2,778,456.89/1,418.80
6. Step 6: Final answer
   x = 1,958.31