Finding the Fourth Proportional to 21,012.35, 28,995.89 and 13,054.41

Step by Step Solution

1. Step 1: Write the proportion equation
   21,012.35 : 28,995.89 = 13,054.41 : x
2. Step 2: Convert to fraction form
   21,012.35/28,995.89 = 13,054.41/x
3. Step 3: Cross multiply
   21,012.35x = 28,995.89 × 13,054.41
4. Step 4: Simplify right side
   21,012.35x = 378,524,171.10
5. Step 5: Solve for x
   x = 378,524,171.10/21,012.35
6. Step 6: Final answer
   x = 18,014.37