Finding the Fourth Proportional to 21,078.02, 29,093.46 and 13,115.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,078.02 : 29,093.46 = 13,115.50 : x
2. Step 2: Convert to fraction form
   21,078.02/29,093.46 = 13,115.50/x
3. Step 3: Cross multiply
   21,078.02x = 29,093.46 × 13,115.50
4. Step 4: Simplify right side
   21,078.02x = 381,575,274.63
5. Step 5: Solve for x
   x = 381,575,274.63/21,078.02
6. Step 6: Final answer
   x = 18,102.99