Finding the Fourth Proportional to 11,915.30, 17,871.48 and 6,920.42

Step by Step Solution

1. Step 1: Write the proportion equation
   11,915.30 : 17,871.48 = 6,920.42 : x
2. Step 2: Convert to fraction form
   11,915.30/17,871.48 = 6,920.42/x
3. Step 3: Cross multiply
   11,915.30x = 17,871.48 × 6,920.42
4. Step 4: Simplify right side
   11,915.30x = 123,678,147.62
5. Step 5: Solve for x
   x = 123,678,147.62/11,915.30
6. Step 6: Final answer
   x = 10,379.78