Finding the Fourth Proportional to 4,900.72, 7,320.80 and 3,928.72

Step by Step Solution

1. Step 1: Write the proportion equation
   4,900.72 : 7,320.80 = 3,928.72 : x
2. Step 2: Convert to fraction form
   4,900.72/7,320.80 = 3,928.72/x
3. Step 3: Cross multiply
   4,900.72x = 7,320.80 × 3,928.72
4. Step 4: Simplify right side
   4,900.72x = 28,761,373.38
5. Step 5: Solve for x
   x = 28,761,373.38/4,900.72
6. Step 6: Final answer
   x = 5,868.81