Finding the Fourth Proportional to 2,686.18, 4,028.28 and 930.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,686.18 : 4,028.28 = 930.72 : x
2. Step 2: Convert to fraction form
   2,686.18/4,028.28 = 930.72/x
3. Step 3: Cross multiply
   2,686.18x = 4,028.28 × 930.72
4. Step 4: Simplify right side
   2,686.18x = 3,749,200.76
5. Step 5: Solve for x
   x = 3,749,200.76/2,686.18
6. Step 6: Final answer
   x = 1,395.74