Finding the Fourth Proportional to 11,815.41, 17,718.57 and 3,915.53

Step by Step Solution

1. Step 1: Write the proportion equation
   11,815.41 : 17,718.57 = 3,915.53 : x
2. Step 2: Convert to fraction form
   11,815.41/17,718.57 = 3,915.53/x
3. Step 3: Cross multiply
   11,815.41x = 17,718.57 × 3,915.53
4. Step 4: Simplify right side
   11,815.41x = 69,377,503.80
5. Step 5: Solve for x
   x = 69,377,503.80/11,815.41
6. Step 6: Final answer
   x = 5,871.78