Finding the Fourth Proportional to 5,151.30, 7,720.18 and 2,931.15

Step by Step Solution

1. Step 1: Write the proportion equation
   5,151.30 : 7,720.18 = 2,931.15 : x
2. Step 2: Convert to fraction form
   5,151.30/7,720.18 = 2,931.15/x
3. Step 3: Cross multiply
   5,151.30x = 7,720.18 × 2,931.15
4. Step 4: Simplify right side
   5,151.30x = 22,629,005.61
5. Step 5: Solve for x
   x = 22,629,005.61/5,151.30
6. Step 6: Final answer
   x = 4,392.87