Finding the Fourth Proportional to 21,832.41, 30,128.57 and 12,879.93

Step by Step Solution

1. Step 1: Write the proportion equation
   21,832.41 : 30,128.57 = 12,879.93 : x
2. Step 2: Convert to fraction form
   21,832.41/30,128.57 = 12,879.93/x
3. Step 3: Cross multiply
   21,832.41x = 30,128.57 × 12,879.93
4. Step 4: Simplify right side
   21,832.41x = 388,053,808.20
5. Step 5: Solve for x
   x = 388,053,808.20/21,832.41
6. Step 6: Final answer
   x = 17,774.21