Finding the Fourth Proportional to 21,915.42, 30,242.83 and 12,355.32

Step by Step Solution

1. Step 1: Write the proportion equation
   21,915.42 : 30,242.83 = 12,355.32 : x
2. Step 2: Convert to fraction form
   21,915.42/30,242.83 = 12,355.32/x
3. Step 3: Cross multiply
   21,915.42x = 30,242.83 × 12,355.32
4. Step 4: Simplify right side
   21,915.42x = 373,659,842.36
5. Step 5: Solve for x
   x = 373,659,842.36/21,915.42
6. Step 6: Final answer
   x = 17,050.09