Finding the Fourth Proportional to 11,815.40, 17,710.59 and 3,915.88

Step by Step Solution

1. Step 1: Write the proportion equation
   11,815.40 : 17,710.59 = 3,915.88 : x
2. Step 2: Convert to fraction form
   11,815.40/17,710.59 = 3,915.88/x
3. Step 3: Cross multiply
   11,815.40x = 17,710.59 × 3,915.88
4. Step 4: Simplify right side
   11,815.40x = 69,352,545.17
5. Step 5: Solve for x
   x = 69,352,545.17/11,815.40
6. Step 6: Final answer
   x = 5,869.67