Finding the Fourth Proportional to 20,871, 28,801.98 and 11,439.63

Step by Step Solution

1. Step 1: Write the proportion equation
   20,871 : 28,801.98 = 11,439.63 : x
2. Step 2: Convert to fraction form
   20,871/28,801.98 = 11,439.63/x
3. Step 3: Cross multiply
   20,871x = 28,801.98 × 11,439.63
4. Step 4: Simplify right side
   20,871x = 329,483,994.47
5. Step 5: Solve for x
   x = 329,483,994.47/20,871
6. Step 6: Final answer
   x = 15,786.69