Finding the Fourth Proportional to 21,011.76, 29,010.42 and 13,066.20

Step by Step Solution

1. Step 1: Write the proportion equation
   21,011.76 : 29,010.42 = 13,066.20 : x
2. Step 2: Convert to fraction form
   21,011.76/29,010.42 = 13,066.20/x
3. Step 3: Cross multiply
   21,011.76x = 29,010.42 × 13,066.20
4. Step 4: Simplify right side
   21,011.76x = 379,055,949.80
5. Step 5: Solve for x
   x = 379,055,949.80/21,011.76
6. Step 6: Final answer
   x = 18,040.18