Finding the Fourth Proportional to 2,218.50, 3,061.71 and 1,287.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.50 : 3,061.71 = 1,287.18 : x
2. Step 2: Convert to fraction form
   2,218.50/3,061.71 = 1,287.18/x
3. Step 3: Cross multiply
   2,218.50x = 3,061.71 × 1,287.18
4. Step 4: Simplify right side
   2,218.50x = 3,940,971.88
5. Step 5: Solve for x
   x = 3,940,971.88/2,218.50
6. Step 6: Final answer
   x = 1,776.41