Finding the Fourth Proportional to 10,491.12, 15,729.39 and 3,915.54

Step by Step Solution

1. Step 1: Write the proportion equation
   10,491.12 : 15,729.39 = 3,915.54 : x
2. Step 2: Convert to fraction form
   10,491.12/15,729.39 = 3,915.54/x
3. Step 3: Cross multiply
   10,491.12x = 15,729.39 × 3,915.54
4. Step 4: Simplify right side
   10,491.12x = 61,589,055.72
5. Step 5: Solve for x
   x = 61,589,055.72/10,491.12
6. Step 6: Final answer
   x = 5,870.59