Finding the Fourth Proportional to 5,641.60, 7,785.69 and 3,123.98

Step by Step Solution

1. Step 1: Write the proportion equation
   5,641.60 : 7,785.69 = 3,123.98 : x
2. Step 2: Convert to fraction form
   5,641.60/7,785.69 = 3,123.98/x
3. Step 3: Cross multiply
   5,641.60x = 7,785.69 × 3,123.98
4. Step 4: Simplify right side
   5,641.60x = 24,322,362.19
5. Step 5: Solve for x
   x = 24,322,362.19/5,641.60
6. Step 6: Final answer
   x = 4,311.25