Finding the Fourth Proportional to 13,978.88, 20,981.28 and 7,058.24

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.88 : 20,981.28 = 7,058.24 : x
2. Step 2: Convert to fraction form
   13,978.88/20,981.28 = 7,058.24/x
3. Step 3: Cross multiply
   13,978.88x = 20,981.28 × 7,058.24
4. Step 4: Simplify right side
   13,978.88x = 148,090,909.75
5. Step 5: Solve for x
   x = 148,090,909.75/13,978.88
6. Step 6: Final answer
   x = 10,593.90