Finding the Fourth Proportional to 10,915.81, 16,376.91 and 3,520.12

Step by Step Solution

1. Step 1: Write the proportion equation
   10,915.81 : 16,376.91 = 3,520.12 : x
2. Step 2: Convert to fraction form
   10,915.81/16,376.91 = 3,520.12/x
3. Step 3: Cross multiply
   10,915.81x = 16,376.91 × 3,520.12
4. Step 4: Simplify right side
   10,915.81x = 57,648,688.43
5. Step 5: Solve for x
   x = 57,648,688.43/10,915.81
6. Step 6: Final answer
   x = 5,281.21