Finding the Fourth Proportional to 11,813.70, 17,721.46 and 3,915.89

Step by Step Solution

1. Step 1: Write the proportion equation
   11,813.70 : 17,721.46 = 3,915.89 : x
2. Step 2: Convert to fraction form
   11,813.70/17,721.46 = 3,915.89/x
3. Step 3: Cross multiply
   11,813.70x = 17,721.46 × 3,915.89
4. Step 4: Simplify right side
   11,813.70x = 69,395,337.20
5. Step 5: Solve for x
   x = 69,395,337.20/11,813.70
6. Step 6: Final answer
   x = 5,874.14