Finding the Fourth Proportional to 2,218.08, 3,061.28 and 1,286.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.08 : 3,061.28 = 1,286.40 : x
2. Step 2: Convert to fraction form
   2,218.08/3,061.28 = 1,286.40/x
3. Step 3: Cross multiply
   2,218.08x = 3,061.28 × 1,286.40
4. Step 4: Simplify right side
   2,218.08x = 3,938,030.59
5. Step 5: Solve for x
   x = 3,938,030.59/2,218.08
6. Step 6: Final answer
   x = 1,775.42