Finding the Fourth Proportional to 21,022.31, 28,994.38 and 13,469.35

Step by Step Solution

1. Step 1: Write the proportion equation
   21,022.31 : 28,994.38 = 13,469.35 : x
2. Step 2: Convert to fraction form
   21,022.31/28,994.38 = 13,469.35/x
3. Step 3: Cross multiply
   21,022.31x = 28,994.38 × 13,469.35
4. Step 4: Simplify right side
   21,022.31x = 390,535,452.25
5. Step 5: Solve for x
   x = 390,535,452.25/21,022.31
6. Step 6: Final answer
   x = 18,577.19