Finding the Fourth Proportional to 21,020.38, 28,991.71 and 13,467.41

Step by Step Solution

1. Step 1: Write the proportion equation
   21,020.38 : 28,991.71 = 13,467.41 : x
2. Step 2: Convert to fraction form
   21,020.38/28,991.71 = 13,467.41/x
3. Step 3: Cross multiply
   21,020.38x = 28,991.71 × 13,467.41
4. Step 4: Simplify right side
   21,020.38x = 390,443,066.54
5. Step 5: Solve for x
   x = 390,443,066.54/21,020.38
6. Step 6: Final answer
   x = 18,574.51