Finding the Fourth Proportional to 21,915.89, 30,242.41 and 12,356.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,915.89 : 30,242.41 = 12,356.12 : x
2. Step 2: Convert to fraction form
   21,915.89/30,242.41 = 12,356.12/x
3. Step 3: Cross multiply
   21,915.89x = 30,242.41 × 12,356.12
4. Step 4: Simplify right side
   21,915.89x = 373,678,876.21
5. Step 5: Solve for x
   x = 373,678,876.21/21,915.89
6. Step 6: Final answer
   x = 17,050.59