Finding the Fourth Proportional to 5,642.59, 7,785.81 and 3,518.78

Step by Step Solution

1. Step 1: Write the proportion equation
   5,642.59 : 7,785.81 = 3,518.78 : x
2. Step 2: Convert to fraction form
   5,642.59/7,785.81 = 3,518.78/x
3. Step 3: Cross multiply
   5,642.59x = 7,785.81 × 3,518.78
4. Step 4: Simplify right side
   5,642.59x = 27,396,573.46
5. Step 5: Solve for x
   x = 27,396,573.46/5,642.59
6. Step 6: Final answer
   x = 4,855.32