Finding the Fourth Proportional to 21,109.59, 29,103.84 and 13,137.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,109.59 : 29,103.84 = 13,137.57 : x
2. Step 2: Convert to fraction form
   21,109.59/29,103.84 = 13,137.57/x
3. Step 3: Cross multiply
   21,109.59x = 29,103.84 × 13,137.57
4. Step 4: Simplify right side
   21,109.59x = 382,353,735.27
5. Step 5: Solve for x
   x = 382,353,735.27/21,109.59
6. Step 6: Final answer
   x = 18,112.80