Finding the Fourth Proportional to 5,156.10, 7,728.68 and 3,920.46

Step by Step Solution

1. Step 1: Write the proportion equation
   5,156.10 : 7,728.68 = 3,920.46 : x
2. Step 2: Convert to fraction form
   5,156.10/7,728.68 = 3,920.46/x
3. Step 3: Cross multiply
   5,156.10x = 7,728.68 × 3,920.46
4. Step 4: Simplify right side
   5,156.10x = 30,299,980.79
5. Step 5: Solve for x
   x = 30,299,980.79/5,156.10
6. Step 6: Final answer
   x = 5,876.53