Finding the Fourth Proportional to 5,171.94, 7,128.07 and 4,221.61

Step by Step Solution

1. Step 1: Write the proportion equation
   5,171.94 : 7,128.07 = 4,221.61 : x
2. Step 2: Convert to fraction form
   5,171.94/7,128.07 = 4,221.61/x
3. Step 3: Cross multiply
   5,171.94x = 7,128.07 × 4,221.61
4. Step 4: Simplify right side
   5,171.94x = 30,091,903.22
5. Step 5: Solve for x
   x = 30,091,903.22/5,171.94
6. Step 6: Final answer
   x = 5,818.30