Finding the Fourth Proportional to 17,915.79, 26,843.76 and 12,642.09

Step by Step Solution

1. Step 1: Write the proportion equation
   17,915.79 : 26,843.76 = 12,642.09 : x
2. Step 2: Convert to fraction form
   17,915.79/26,843.76 = 12,642.09/x
3. Step 3: Cross multiply
   17,915.79x = 26,843.76 × 12,642.09
4. Step 4: Simplify right side
   17,915.79x = 339,361,229.86
5. Step 5: Solve for x
   x = 339,361,229.86/17,915.79
6. Step 6: Final answer
   x = 18,942.02