Finding the Fourth Proportional to 21,941.43, 30,270.56 and 12,985.67

Step by Step Solution

1. Step 1: Write the proportion equation
   21,941.43 : 30,270.56 = 12,985.67 : x
2. Step 2: Convert to fraction form
   21,941.43/30,270.56 = 12,985.67/x
3. Step 3: Cross multiply
   21,941.43x = 30,270.56 × 12,985.67
4. Step 4: Simplify right side
   21,941.43x = 393,083,502.88
5. Step 5: Solve for x
   x = 393,083,502.88/21,941.43
6. Step 6: Final answer
   x = 17,915.13