Finding the Fourth Proportional to 14,090.88, 21,128.76 and 13,485

Step by Step Solution

1. Step 1: Write the proportion equation
   14,090.88 : 21,128.76 = 13,485 : x
2. Step 2: Convert to fraction form
   14,090.88/21,128.76 = 13,485/x
3. Step 3: Cross multiply
   14,090.88x = 21,128.76 × 13,485
4. Step 4: Simplify right side
   14,090.88x = 284,921,328.60
5. Step 5: Solve for x
   x = 284,921,328.60/14,090.88
6. Step 6: Final answer
   x = 20,220.27